When expansion of the ILTMS (International Leased Telegraph Message Service) later named "Primex" was necessary, the building that formerly held Brent Radio Telephony Terminal was upgraded and pressed into service, this ran from 1976 until around 1982. Gladstone B exchange shared the building. This North London site was near to Brent Cross Shopping Centre. Nothing now exists of the building and the site is now an overflow car park for the Shopping Centre.
The forerunner of the message switcher was the Hasler M100 unit that was in use at St. Botolphs. This was followed by the next generation M150s which offered multiple and various speed TGPs and Telex access. They used the message switching format :"zczc destination code, originator code, date/time, preamble and ending with nnnn.
The first set of pictures below were provided by Phil Ryan.The array of World Time clocks on the FRC were Steve Enderson's idea, unfortunately they were unsynchronised so they always a few minutes off their correct time, but it was a good idea.