The various numbers and markings which are generally be found in between the spirals of a record's run-off groove can be a help in identifying which company made that pressing.  Judging by a quick look at singles in my collection it seems that different pressing plants had different styles of run-off 'legend'.  CBS, Decca, EMI, Philips/ Polydor, Pye, and (in the second half of the decade) RCA appear to have had distinctive and easily recognizable styles, so a few notes about them may be useful.  There were of course a lot of other pressing firms, some of which had their own particular styles; I've been able to identify some of them - Orlake, and possibly British Homophone and Saga - but others remain elusive.  What follows is not authoritative; as I said, it comes from observation, not from first-hand knowledge.

Run-off legends come in different forms - hand-written or typefaced - and in different positions.  They tend to consist of the matrix number of the record with a few add-ons at the end.  The matrix number is often accompanied by a 'cut number', which refers to the 'stamper' (the metal plate being used to press that side of the record).   Other numbers, letters or symbols can often be found in association with the matrix number or at other places on the run-off; these refer to things such as the 'take' (which version of a recording is being used).   Firms, or individual engineers, responsible for cutting the records sometimes added initials, names or even messages: Utopia studios used a lyre-like mark to identify its cuts.  Making a record involves several stages, and marks can be added at each - it should be kept in mind that once a stamper has been made by one firm it can be taken to a different firm for the actual pressing to be done.  Identification, therefore, is likely to be less than an exact science, and the following guide should be approached with caution.  I would only claim that it is better than nothing.  A comprehensive list of the various markings and their meanings can be found at

While reading the following descriptions it helps to think of the record as a kind of clock-face.  Position the run-off legend so that it's the right way up.  If it's at the top of the record, that's twelve o'clock; if it's at the bottom, that's six.  The three and nine o'clock positions are where you'd expect them to be, as are all the rest of the hours.  So if the description says there's an '04' at ten o'clock you should know where to look for it.  He said, hopefully.

* * * * *



CBS run-off legends from 1970-c.76 are typefaced and can be found at twelve o'clock.  The basic matrix number
(which is generally the same as the catalogue number but with an 'A' or a 'B' added, indicating whether that side of the record is the 'A' or 'B' side) is followed closely by a single number, which presumably refers to the 'stamper' or the 'take'.  The parts of the legend may be separated by hyphens or dots or they may be left blank.  Typical examples would be 'CBS S 7986 A1' from 1972, 'CBS-S-2327-A2' from 1974, or 'EPCS 2151 B1', an Epic single from 1973.


At nine o'clock there are usually three dots, making the points of a small triangle; sometimes these dots have faint lines partially joining them, suggesting a badly-formed 'A'; on better-selling singles this may be a shallowly-impressed letter such as B, C or D, which lends support to the 'A' theory.  The example shown is a 'D'.  At three o'clock there are usually one or two numbers; again these may be so faintly impressed as to be barely legible: I've managed to scan a '2' and a '5' as examples, but it wasn't easy and the results aren't good.  Around 1977 the typefaced legend was replaced by a handwritten one but the layout remained the same, as can be seen in the third and fourth examples shown above.  The symbols at three o'clock and nine o'clock remained unchanged.

* * * * *


With occasional exceptions Decca run-off legends are typefaced.  They can be found at 6 o'clock.  The basic matrix number, which usually bears no relation to the catalogue number, is followed by a 'T' and a single number, and then by another single number and a letter - generally a '1' and a 'C' or a 'K'.  The various parts of the legend are separated by hyphens.  An example would be 'ZDR-56491-T1-1C'.  The 'Z' seems to indicate a stereo recording, an 'X' a mono one.  EMI legends are similar but they tend to be more widely spaced and to lack all but the last of the separating hyphens.


At nine o'clock there is a single number, usually '1' but sometimes higher; Keith Stephens has been kind enough to mail in and say that this number was the 'mother' number - it referred to the metal 'mother' which was an integral part of the pressing process.  At three o'clock there is usually a letter which, Keith points out, indicates which stamper was used to do the pressing.  Decca used the letters of the word BUCKINGHAM to indicate the letters 1 to 10; thus a 'B' at 3 o'clock indicates a first stamper, 'K' a fourth, and so on.  The letters could be used in combination, thus a 'BU' would be from the twelfth stamper.  Each stamper was used to make approximately five hundred pressings, so for a popular record they had to be changed regularly.

* * * * *


EMI run-off legends are placed at 6 o'clock, and come in a widely-spaced typeface.  The basic matrix number is followed by a hyphen, then a single number, usually a '1'.  Thus we have 'SHAR 5113 B-1' for Harvest, 'YPUR 120 A-1' for Purple, and 'EMI 2397 A-1' for the EMI label.  For labels where the matrix number is very different from the catalogue number, as is the case with Columbia and Parlophone, the results look like '7XCA 33002-1' and '7YCE 21469-1'.  An 'X' in the matrix number generally indicates a mono recording, a 'Y' a stereo one, the 'WIPX' of the Island label (shown below) being an exception. 


Some EMI pressings can be found with a 'U' after the single number, giving 'UP 35760 A-4U', 'BELL 1299 B-1U', 'ARISTA 1 A-1U', MAG 127 B-1U' and so on.  Phil Elliott has been kind enough to get in touch to explain that this 'U' indicated that the mastering had been done somewhere other than at EMI's own Abbey Road facilities; it was first added c.1970.  Decca legends are similar but the letters are more closely spaced and always run in a straight line; the various parts of Decca legends are generally separated by hyphens.


Away from the run-off legend there is usually something which looks like either a '1', a reversed '1', or an '!' at nine o'clock.  There is a letter, or a pair of letters, at three o'clock; Keith Stephens has kindly informed me that, as is the case with Decca recordings, these refer to the different 'stampers' that were used to make the pressings.  According to Keith, EMI used the letters GRAMOPHLTD to represent the numbers 1 to 10, so that a record with 'G' at 9 o'clock would be from the first stamper, and 'T' from the ninth, while 'GM' would be from the fourteenth.  On records dating from around 1963 until early September 1973 the initials KT can often be found, inverted, at twelve o'clock.  This refers to the purchase tax payable on the record. In addition, where a record has been perforated so that its centre may be pushed out, the perforations on EMI pressings (and those of RCA from Spring 1975 onwards) are noticeably narrower than those of the other companies, which offers an initial readily observable clue as to a single's origins.

* * * * *


Philips and Polydor shared a close association.  In the '70s their records were pressed at the Philips (renamed 'Phonodisc') plant in Walthamstow.  The legend action - for want of a better description - on records in the Philips / Polydor groups and their successors all takes place at the top of the record, and the legend is typefaced.  The basic matrix number is at twelve o'clock: for Philips / Phonogram singles it consists of the catalogue number followed closely by a '1F' (for an 'A' side) or a '2F' (for a 'B' side).  Then come two forward slashes, a single number (usually a '1' or a '2'), an inverted triangle and (usually, for British singles) the number '420'.  For example you might find '6006160 1F//s420' (Philips), '6059026 2F//1s420' (Vertigo), or '6076002 1F//1s420' (Nashville).   'Seb' has written in to identify the various components: the first '1' or '2' after the catalogue number are side identifiers; the 'F' is the 'media identifier' and indicates that the record is a 7" ('Y' would mean a 12" or an LP); the number before the inverted triangle is the 'lacquer cut sequence number'; and the number after the triangle is the 'lacquer cut machine number' - it indicates what country the lacquer was cut in.  Keith Stephens has been kind enough to send the following list of machine numbers and the countries in which they were used; Tapio Keihanen has kindly filled in some gaps in the original list but it may still be incomplete:

Austria - 720;  Australia - 150;  Belgium - 170;   Brazil - 200;   Canada - 230;  Denmark - 300; Far East - 022;  France - 380;  Germany - 320;   Great Britain & Ireland - 420;  Greece - 410, 310;   Holland - 670;  Hungary - 450;   Italy - 520; Luxembourg - 630;  Norway - 710;  Netherlands - 670;  Norway, Sweden - 710;   Portugal - 790;  South Africa - 960;   Spain - 850; Sweden - 970 (uncertain);  Switzerland - 980;  Rest of the World - 000.

Seb' has also provided the following information about lacquer markings:

Phonodisc used characters to denote an outsourced lacquer cut:
sE where 'E' stands for 'External'. The matrix number would look like: CB 363 A // 1sET RAYS .
In that example 'RAYS' stands for Ray Staff, mastering engineer at Trident from 1970 to 1986.
The following studios were used:
Abbey Road (sEAR);  CBS (sEC);  Decca (sED);  Kendun Recorders (sEKR);
Master Room (sEM);  CTS (sEMC);  Master Disc (sEMD);  Pye / PRT (since 1980) (sEP);
Portland (sEPS);  The Sound Clinic (sESC);  Sterling Sound (sEST);  Strawberry Mastering (sESTR)
Trident (sET);  Townhouse (sETH);  Tape One (sETO);  Utopia (sEUT).

Polydor group matrix numbers are almost identical to Philips / Phonogram ones, except that that the 'A' and 'B' sides are indicated by 'A' and 'B' instead of by '1F' and '2F'.  Thus we get '2058110 A//1s420' (Polydor) and '2025193 B//1s420' (Stax).  There are occasional exceptions to these rules - sometimes the triangle or the '420' may be omitted or replaced by a letter, or the two forward slashes may be missing (as in the example shown above) - but the side-indicator seems to be ever present.

Two other number combinations generally appear on the run-off: '04' (sometimes '05' or '03') can often be found either at 10 o'clock or following the matrix number, and three other numbers, often with spaces between them, appear at around two o'clock.  Often these three numbers consist of two '1's (sometimes one of them is reversed) and a '1', '2', '3' or '4'.  'Seb' identifies these as the 'Father number', the 'Mother number', and the 'Stamper number', in that order.  Spacing varies wildly: usually the two '1's are close together, but the third number can be found near to them or anywhere else up to nine o'clock.

Labels which were pressed by Phonodisc but were not part of the Philips / Phonogram or Polydor families appear to have usually followed the Polydor style of run-off legends, for example 'RESL 31 A//1s420' (BBC) and 'EAG 0032 B//1s420' (Eagle); again, parts might be substituted, as happened to the triangle and the '420' in 'BIG 523 A//1 M' (Transatlantic), or missing altogether, like the triangle in 'MAG 005 B//1 420' (Magnum).
Thanks to Keith, Tapio and 'Seb' for all the information they have supplied.

* * * * *



The Pye run-off legend can be found at six o'clock.  It varies in form, being typefaced from 1970-c.76 and
handwritten from then on, though handwritten ones can be found earlier in the decade.  The typeface varies: from 1970-c.73 it generally looks rather rough, from c.1973-c76 it looks a bit thin.  The legend consists of the matrix number (generally the same as the catalogue number, with a suffixed 'A' or a 'B' signifying the 'A' or the 'B' side) followed by a hyphen, a single number (usually '1'), a diamond, a triangle or a star, and finally one or (from c. 1977) two letters.  This results in a typefaced 'DJS 232 B-1 *T' for DJM in 1970, a typefaced '7N 45554 A-G' for Pye in 1975, a typefaced 'KSS 701 A<>X' for a 1974 Kama Sutra, and a handwritten 'EMBS 366-A-1-<>MB' for a 1978 Ember.  There are of course exceptions to this rule, as shown in the third illustration, which is of a Bradleys single from 1974, where the symbol and letter(s) at the end are missing, but it seems to be generally reliable.  'Seb' has kindly sent along the following, which sheds light on the various symbols:

The symbols stand for the cutting room/lathe machines.
Diamond: Identifying the Westrex Scully stereo suite until 1974; from then on identifying the Neumann SX74 suite.
Triangle: Identifying the second Westrex Scully stereo suite until 1967; from 1967 onwards identifying the Neumann SX68 suite.
Star: Identifying the Westrex Scully Mono suite until c.1974.
The alphas after the symbols are for the cutting engineers:
F = Bill Foster;   G = Gordon Vicary;   H = Howard Barrow;   J = Geoff Calver;   T = Tony Bridge
W = Derek Strickland;   X = Ian Cooper;   BJ = Bob Jones;   MB = Mike Brown
So, a *T indicates that Tony Bridge cut the record in the star suite with the Scully lathe.
Other symbols:
Pi symbol = Mike Brown;   NOEL = Noel Summerville;   TONE = Tony Bridge

Thanks to Denis Blackham for supplying Bill Foster's name.


As for other markings on the run-off, there is a letter (sometimes two letters) at nine o'clock, and a number, generally '1', at three o'clock.  These are handy, in that they help distinguish between Pye pressings, which have them, and Saga pressings (see below), which don't.  In the '70s Pye pressings were often done on a kind of vinyl which appears a translucent wine red when held up to direct light, which is a useful identifying characteristic.  There doesn't appear to be any distinction between run-off legends of Pye Group records and those of records which Pye manufactured and distributed for other companies.

* * * * *


From the start of the decade until the spring of 1975 the run-off legends and the other markings on RCA singles - including associated labels such as Rockfield - are often pretty much identical with those of CBS singles, as CBS did a lot of the pressing: typefaced matrix numbers plus another single (stamper?) number at twelve o'clock; an 'A', often degenerated into a three-dot 'therefore' kind of mark at nine o'clock; and usually one or two numbers (often faint) at three o'clock.  RCA singles, however, often have a letter 'E' after the 'stamper' number (if that is what it is).  At first the matrix numbers of RCA records were vastly different from the catalogue numbers, but in 1973 they became more or less identical, with only a suffixed 'A' or 'B' (indicating the 'A' or 'B' side of the record) to distinguish between them.   With the component parts added together, what we see in the run-off is something akin to 'BGBS 0992 1E', or 'RCA 2411 A 1E'.  RCA pressed many of its own albums during the first half of the decade, but it also seems to have pressed a limited number of its own singles.  One of the few examples that I have seen and of which I can be pretty sure can be seen in the first picture shown above.  The matrix numbers are in a typefaced font, set in a slight curve at six o'clock; the number itself has a '1E' after it, separated from it by a hyphen, as the CBS pressings did.  Elsewhere on the run-off there is a handwritten three-digit block such as A1A, A1C, and so on - their appearance is similar to the example shown below.  The labels of these early self-pressed singles had shiny-looking labels and a ring 25mm in diameter around the spindle hole.  Confusingly some CBS pressings from slightly later (1974-75) also have that 25mm ring, but the labels do not have the same shine to them.  In early 1975, however, RCA developed a style of its own - presumably it started pressing all its own singles at that point (it had been increasingly responsible for pressing its own albums from mid 1969).   As can be seen from the example shown in the second picture, the matrix numbers bore a close resemblance to those of the earlier self-pressed singles, except that the characters were handwritten; and they can be found in the same position, at six o'clock.  It was usual for some of the components to be separated by hyphens, as in 'PB 5099-A-2E' and 'GO 336-A-1E'.

As a rule there were two other marks on the run-off during this later period: a 'letter number letter' triad, such as 'A1C' or 'A1H',similar to that on the earlier self-pressed records, and a letter 'W' in inverted commas.  These could be found at any point around the run-off; popular places for the triad were at three o'clock and nine o'clock, while the 'W' often turned up at twelve.  On occasions the triad adds an extra letter or two, as in 'A1AT' or 'A1AAB'.  Thanks to Keith Stephens for additional information.

* * * * *


For the greater part of the 1970s labels in the Kinney / WEA group were pressed by CBS, the two companies having shared manufacturing and distribution facilites, and therefore they have CBS-style markings.  WEA was an ambitious concern, however.  It set up its own distribution network, which came into operation in early 1976, and purchased Island's pressing plant when it came up for sale in January 1978.  According to Billboard magazine (21st January) its manufacturing agreement with CBS still had more than a year to run, but the plant was available for overflow work and third-party pressings.  In that same year WEA invested in Damont, which had another pressing plant, and by February 1979 Damont had become part of the WEA group.  This gave WEA two separate facilities to employ when it struck out on its own, which it appears to have done around the end of 1978.  Its singles from then on can be divided into two distinct types.  Singles of the first type have anti-slip ridges around the labels and often have a 'D' at twelve o'clock: it seems reasonable to guess that these are Damont pressings, particularly as in the early '80s the 'D' was sometimes replaced by a 'DAMONT'.  The second type of single has no anti-slip ring and no 'D': I have no proof that these came from the ex-Island plant, but it seems not impossible.  Singles of both kinds frequently have marks from studios such as Strawberry, suggesting that mastering was done by independent facilities.  There are some differences in the run-off markings of the two types, and it is to these that we now turn.  As ever, I would like to point out that what follows is a generalization, and that there are exceptions here as there are everywhere else on this page.



The matrix numbers themselves are at six o'clock, and are handwritten.  The numerical part is usually without hyphens, but they seem to be optional after the 'A' or 'B' side indicator.  There is often a number at three o'clock and a letter at nine, and the overall effect is similar to Pye pressings.  Unlike Pyes, however, there is a 'D' (sometimes underlined, and sometimes quite fancy, as below) at twelve o'clock, and the WEAs lack the distinctive star / diamond / triangle markings which indicate Pye mastering.


WEA (Ex-Island plant?)


Again, the matrix numbers are handwritten, are at six o'clock, and can be found with or without hyphens.  Elsewhere in the run-off there are often the names or logos of the studios which were presumably responsible for doing the mastering; there are other marks too, such as combinations of the letter 'S' and a number, 'EG', or WEA T/P'.  The 'S' appears to refer to Strawberry studios, which presumably did some mastering for WEA.  A number can be found either at three o'clock or at nine o'clock.


* * * * *


A pressing plant from the Dagenham area, Orlake pressed singles for any number of independent labels during the '70s, and it is still in operation today.  It manufactured many of Trojan's singles, both on the actual Trojan label and on the subsidiary labels.  Orlake products often have a '+' separating the different parts of the matrix number, as in 'HOSS+18+A'.  The numbers may be typefaced or handwritten.  Sometimes the letters 'OR' can be found.  The labels on Orlake pressings tend to have rather rough surfaces, often with a smooth outer rim.

* * * * *



A long-lived independent pressing plant, British Homophone was founded in 1921.  It issued records on its own labels until 1935, and continued to press records for other companies until at least the mid '70s.  The company pressed some Doctor Bird singles and was owned at some point in the '60s and '70s by President Records boss Ed Kassner, so, because my sole Doctor Bird and most of my few Presidents have run-off markings in the style shown above, I hope and trust that that is, indeed, the British Homophone type of marking.  Jim West, the owner of the small independent West Records, says that he used British Homophone for his pressings, and the markings on the few West records that I have seen are similar, which boosts my confidence somewhat - the second example above is from one of his EPs.  Working on that premise, until some time in 1974 its style of matrix numbers was distinctive: as can be seen from the above illustration the numbers, which appeared at six o'clock, were quite bold and deep; often there are tiny circles at the end of the various lines that make up the figures, as though something like a dentist's drill has been used to make them.  That style of marking can be found on the records of a large number of small companies, such as Dancetime, which presumably were British Homophone customers.  It seems to have fallen out of use in 1974.  From that time onwards President group records often have a less distinctive kind of number; generally hyphenated and at times bold, as shown below.


* * * * *


An independent pressing plant, based in Upper Holloway, London.  Lyntone was a prolific firm: from the early '60s into the '90s it manufactured for literally hundreds of minor labels and also undertook contract work for some of the majors.  Sometimes its name is mentioned on the labels, but the things to look out for are the Lyntone matrix numbers which appear in the run-offs, often in tandem with the originating company's matrix number.  They have an 'LYN' prefix; in the '70s the numbers run from the 1900s up to the high 7000s.  The two sides have consecutive numbers, the example shown having 'LYN-3517' on the reverse.  Lyntone singles tend to have no anti-slip rings. 

* * * * *



Based in Kensal Road, London W10.  Saga is probably best remembered for its budget LP labels, but a pressing plant, 'Allied Records', was part of the same group of companies in the late '60s and the '70s, and a second, separate, plant was set up in March 1973.  In 1975 Saga took over the revamped Trojan and B&C labels, at which point, presumably, it started pressing their singles itself, through its Allied arm or through the new company.  If that is indeed the case, it enables us to identify Saga's style of matrix number at this period.  As can be seen in the example shown above, the number appeared at six o'clock and was in the form 'TRO 7990 A-1'.  This is similar to one of the forms used by Pye, the one without the symbol and letter(s) at the end - see the third illustration in the Pye section.  Saga singles, however, don't have the additional letter at nine o'clock and number at three o'clock that Pye singles have.  The Saga-era Trojan and B&C singles which I have been able to examine have all had shallow anti-slip rings around the label.  There are records on other labels with this style of matrix number but without that anti-slip ring; I have no evidence that would connect them to Saga - some of the ones from the end of the decade may possibly be WEA products (see above).

* * * * *




A Leicester-based independent pressing firm.  I only have two singles that I know were pressed by ICP, but the style of their run-off markings has some features which seem to be distinctive.  The matrix numbers are in a typeface and can be found in the six o'clock position.  The letters and numbers are rather thin, and the bar on the letter 'A' is rather low, as can be seen from the illustration.  Some singles have anti-slip ridges around the edge of the labels, others do not; they do, however, seem to have a pronounced 'moat' nine or ten millimetres away from the spindle hole and a noticeable bevel (around 6 mm wide) further out - I haven't been able to examine enough definitely-ICP singles to be sure that that was always the case; it may well not have been.  ICP seems to have pressed records for a number of independent labels, including Budget LP concern Deacon.  Records with a similar style of matrix number can be found under Sound News Productions, below.

* * * * *



Sound Manufacturing had registered offices at 14 New Burlington Street, London W1, and a pressing plant in Hayes.  'Billboard' of the 15th of September 1973 reported on the opening of the plant, and said that under its managing director John Wooler - previously with EMI - it specialized in 12" records and had the capacity to fulfil orders of between 50 and 1,000 copies.  It did however press some 7" records.  In addition to the matrix number some of its products had a distinctive 'Delta plus four-figure number' mark in the run-off (2); some just had the four-figure number; while others had a 'K' or a diamond, followed by a three-figure number (3, 4).  The matrix numbers on the only two Sound Manufacturing 7" records that I have seen in the vinyl were similar in looks to those of Industrial Commercial Plastics (see the previous item) being thin-stemmed and typefaced, but there were slight differences: the Sound Manufacturing figure '1' had a serif, and its figure '2' had a smoother stem than the ICP one, lacking the 'knee and lower leg' part.  With any luck you'll be able to see the differences in the scans shown under the two headings.  Thanks to Jake Jeffers for confirming the existence of the Sound Manufacturing plant and that the delta (or triangle) numbers and 'K' numbers were indeed peculiar to its pressings.

* * * * *



An offshoot of television merchandising and budget-record firm Multiple Sound Distributors. Multiple Sound pressed records for the likes of Pickwick, K-Tel, Readers Digest and Chevron, as well as its own Warwick label.  I have only been able to inspect three 7" records which I am pretty certain were made by the firm, all of them dating from the late '70s or 1980, so what follows should be approached with care.  The records did have one feature in common: a star after the matrix numbers, on one or both sides.  The matrix numbers were at six o'clock and were handwritten; the constituent parts were separated by hyphens in two out of the three cases - the second scan shown above has had the original markings written over, to increase legibility.  Pye singles sometimes had a star in their matrix numbers, but they had other markings on the run-off as well (see above) while the Multiple Sound pressings do not.  In addition, Pye pressings have regular and quite prominent anti-slip rings, whereas those on the Multiple Sound records are either faint, partial or absent altogether, as in the second example shown.  It would be useful to have more examples, as a check, but until they come along it would appear that the stars are the main things to look out for.

* * * * *


Different from the other companies on this page, in that for much of its existence it seems not to have done its own metalwork but to have pressed records using masters supplied by other firms.  As a result there don't usually appear to be any distinguishing marks in the run-offs.  What follows is therefore not 100% certain, but I'm quietly hopeful that it's accurate.  Linguaphone had a big pressing facility; at the time it was sold on, in 1986, it was capable of turning out 125,000 singles a week ('One to One' magazine, November 1986).  There should, therefore, be an awful lot of Linguaphone-pressed singles out there.  According to 'Music Week' of the 14th of June 1975, Zel-La were getting at least some of their singles pressed by Linguaphone; and in the issue of the 8th of April 1978 'MW' said that Linguaphone were doing Big Bear's pressings.  Two Big Bear singles of the time and one of the earlier Zel-Las have the same quite distinctive indentations on their labels, indentations which can also be found on some singles on the Linguaphone label.  In addition Andrew Titcombe has been kind enough to confirm that singles on his Keswick label were made by Linguaphone, and these, too, have the same markings.  I strongly suspect, therefore, that those indentations show that a given single was pressed by Linguaphone.  They consist of a distinct bevel, its outer edge approximately 58mm across, its inner approximately 45mm across, and a slightly raised area, some 25mm wide, around the spindle hole.  In the examples shown below the bevel has been strongly emphasized in order to make it properly visible.


There are many singles around with similar markings, which would correspond with Linguaphone being a prolific presser.  Many are from the smaller companies, ones which didn't have their pressings done by the majors.  It would appear that those companies had the metalwork done elsewhere - perhaps by a firm such as Gedmal Galvanic of Leicester, which did metalwork but not pressing - and then took it to Linguaphone to get the pressings done.  I can't offer definite proof but I think that it seems likely.  Some RCA singles have the marks, too, which suggests that CBS (which pressed most of RCA's singles at the time) may have turned to Linguaphone when its own presses were fully booked.
Early in the decade singles can be found which have the same markings but with the addition of a narrow 'canal' around the inner raised area.  Many Linguaphone singles have these, which leads me to think that they, too, may be indicative of Linguaphone pressings.  The theory is supported by the fact in 'Record Retailer' of the 13th of June 1970 it was said that along with EMI and Decca 'an independent firm in Slough' (where Linguaphone was based) was helping Pye to press copies of Mungo Jerry's 'In The Summertime', and some copies of that EP have the bevel, the raised area and the 'canal'.  Again, some RCA singles have the 'canal' along with the other marks.  Examples are shown below.

This doesn't add up to proof that Linguaphone was responsible for singles with these marks, but I like to think that it's reasonably strong evidence.

* * * * *

* * * * *

The following table should give a rough guide to matrix number and run-off variations.
The information given refers only to 'A' sides, for the sake of simplicity.

CBS Run-off legend, typefaced before c.1977, handwritten afterwards, ending in A1 One or two numbers, often faint (Nothing)

Triangle of dots (= A), or letter

DECCA (Nothing) Letter; B, U, C, K, I, N, G, H, A, or M (Indicates stamper number) Runoff legend, typefaced, hyphens, ending in T1-1C, T2-1C, or similar Number (Indicates which metal mother was used)
EMI Tax code letters - KT in the '70s - until September 1973, upside down. Letter; G, R, A, M, O, P, H, L, T, or D (Indicates stamper number) Run-off legend in wide-spaced type; ends -1, -A1 or -A1U '1' or reversed
PHILIPS Run-off legend, typefaced, containing '1F//', inverted triangle and '420' Three numbers with differing separations; first two often '1's (Nothing) '03' '04', '05'; nearer ten o'clock, can also be at two
POLYDOR Run-off legend, typefaced, containing 'A//', inverted triangle and '420' Three numbers with differing separations; first two often '1's (Nothing) '03' '04', '05'; nearer ten o'clock, can also be at two
PYE (Nothing) '1' Run-off legend ending with '-1' or other number, often followed by a triangle, a star or a diamond and one or two letters Letter
RCA (1971-75?) (Nothing) Possibly 'letter-number-letter' - can be found elsewhere Run-off legend, typefaced and curving, often ending in '-1E' or similar.  Glossy labels, with 25mm diameter ring around spindle hole.  Matt labels with that ring appear to be CBS pressings.

Possibly 'letter-number-letter', if not elsewhere

RCA (1975 on) Possibly 'W' - can be found elsewhere Possibly 'letter-number-letter' - can be found elsewhere Run-off legend, handwritten, often ending in '-1E' or similar Possibly 'letter-number-letter', if not elsewhere
ORLAKE (Nothing) (Nothing) Matrix number, typefaced or handwritten, its components often separated by a plus sign (Nothing)
WEA (Type 1) Often 'D' Number, often '1' Matrix number, handwritten Letter
WEA (Type 2) Number - at 9 o'clock if not here Matrix number, handwritten Number, if not at three o'clock


(Nothing) (Nothing) Matrix number, typefaced, very obvious, sometimes suggestions of circles at the end of lines (Nothing)


(Nothing) (Nothing) Matrix number, handwritten, usually with two or three hyphens.  Look for circle of roughness, around three and a half cm, in the centre of the label. (Nothing)
LYNTONE (Nothing) Alternative catalogue number somewhere on the run-off Matrix number, handwritten, with an LYN prefix (Nothing)
SAGA / ALLIED (Nothing) (Nothing) Matrix number, ending in '-1' (Nothing)
ICP (Nothing) (Nothing) Matrix number, typefaced, thin. 'A's have low bars.  No serifs on '1's, '2's have kink in stem. (Nothing)
SOUND MANUFACTURING (Nothing) (Nothing) Matrix number, typefaced, thin. Serifs on '1's, no kink in stem of '2's. Triangle and four-figure number - perhaps can be found elsewhere.
MULTIPLE SOUND (Nothing) (Nothing) Matrix number, handwritten, with a star at the end.  May have hyphens. (Nothing)