EMI Made a variety of tonearms well into the 70's, some of the more usable models are the oil damped unipivots from the late 60's esp. the bigger broadcast models that came with a combination of a headshell and a cartridge, junk the cart and you have a nice vintage arm for you SPU.
EMT Studiotechnik The earliest EMT arms are 12" OEM models from Ortofon but the company later made the 929 unipivot mostly for supplying with their own table but they turn up from time to time on other decks. Note that the heashell for this arm and some other EMT arms uses a Neumann connector (usually called an EMT headshell now) and is not compatible with standard headshell.
Electro Sonic Laboratories (ESL) Odd this, looking at an ESL Gyro Balance 1000 and other of their late 50's, early 60's models it's very similar to old Ortofon arms, however in a 50's guidebook to hi-fi ESL is listed as a Danish company, so it not an OEM name, could be that Ortofon used this name for the US and Asian markets, that this was another Danish company that exported Orto products under it's own name or that this was a trade name used by them in between the original Fonofilm name and the one they use now. Anyhow, has a nice and smooth but not very detailed sound like so many vintage arms.
Expert A model of a vintage "Expert Moving Coil Pickup" and arm were offered for sale recently but came with no information, if someone out there has any info please get in touch. One of the best looking arms ever made.
Exclusive The EA-10 is another one of those 70's arms that is currently being sold for very high prices but I cannot find any further info on.
Farchild Made a range of transcription arms from the 50's into the late 60's, all models that I have seen are 12" and while the earlier models such as the Model 282 should not be placed on a modern deck the slightly later Model 500 is sought after by collectors.
Fidelity Research Made a well regarded line of arms to along with the cartridges that were their main line of business. The FR-64 series is probably the most common on the second hand market, the FR-64fx with a black anodised aluminium armtube and the FR-64s wich featured a Steel alloy tube are usually considered better than the plain model (that had an aluminium armtube if I remember correctly), the 64 series was made in the 70's and the MkII versions in the early 80's. The earlier FR-54 was not as well regarded and can usually be had cheap and the FR-66 line the most sought after, again the FX & S variants considered better. The 66 is a 16" arm, was the first tonearm to allow for on-the-fly VTA adjustment, it's not a transcription tonearm the 16" size is to minimise tracking errors. Also note that the FR-6x series arms could be ordered with internal silver wiring, but the markings on the arms are the same only the package has a silver coloured sticker to show this, and nota bene these are all high mass arms.
Forsell The Air Bearing arm that is supplied with their Forsell Reference Series Turntable turntable actually predates the turntable itself and was in or around 1980 sold as a seperate unit although currently it's is only avaiable with the deck.
Garrard While most arms that you will see sold from this company ware replacement arms for their turntables they actually did make separate transcription tonarms in the late 50's /early 60's that were called TPA-10 and TPA-12 and can be fitted on any deck, while not great, they have a lovely retro chic.
General Electric Made arms well into the 60's, amongst their later models was the TM-2G Stereo Classic from the early 60's, by that time their arms were mostly intended for home hi-fi rather than transcription use.
Goldmund The electronically controlled tangential arms T3 arm introduced in 1978 was the first product from the company, although it was not produced in any numbers until 1981, an upgraded version named the T3F was introduced in 1985, there was also a model availeble called T5 that is believed to be a less expensive variant.
Grace Small Japanese company made a big splash when it came out with the first oil damped tonearms in the 50's, this page here has some minimal info on them. While the Japanese "single ended" crowd mostly hunts out for their 50's damped models and the 60's G340 and G440 models, the 60's and 70's era G-704, 840-F and the wood bodied 714 are more sough after in the west. The G-707 was introduced in the late 60's and continued in production well into the 80's, the original design replaced by the MkII in the mid 70's. This is by far the most commonly seen arm from the company and it was considered to be something of a bargain at the time, works well with high compliance carts.
Graham Engineering Makes a well regarded unipivot arm available in a few versions, namely the 2.0 that is their cheapest model the new 2.2 model that features an improved bearing system (you can upgrade the 2.0 to 2.2 spec at a later date and if you think that unipivots are only for low mass MM designs the company also makes the Nightingale a combination tonearm and high end MC pickup just to prove you wrong.
Graham Engineering This company has been constantly refining their unipivot arm design, this means that if you have a 1.5t or 2.0 arm you can upgrade it to the specification of their current 2.2 arm, as this is a bearing upgrade it's definitely worthwhile. No such luck for owners of older versions (bit odd since the only difference between the 1.5 and T was that the T model had Tungstein weights, and this was supplied by the company as a user upgrade at the time). The 1.5t/C was a version with a ceramic SW-3 armtube and was reviewed by Stereophile in 1995 and an archive of that review can be found here.
Gray Research This American company manufactured preamplifiers and tonarms such as the 103-SL for transcription turntables in the 40's and early 50's, and we mean REAL transcription tables, those that are the size of a refrigerator and the 103 is indeed a heavy design that is not advisable to put onto a modern deck. In the mid 50's they however introduced the 108 series, a viscous damped unipivot that was considered THE arm to have by American audiophiles well into the early 60's and was made in quite a few variations, most of them 12" or 14" in length and are fairly easy to get on the second hand market. Later models such as the 12" 212 a design similar to the 108 but made out of aluminium are more difficult to get hold of.