To go back to your original question, during the 1970s/early 1980s, I came across the following trailers:
3 (Airportable) Div HQ & Signal Regt, Bulford -
equipped with C50/R236 radio-relay station (2 banks)
equipped as "Radcon" (Rado control) for the radio comcen
8 Signal Regt, Catterick -
3 trailers equipped with SR C41/R222 for a specific "Wartime Role"
34 (Eastern) Signal Regt (V) -
equipped with SR C41/R222
The trailers were used in the C41 role, and in the C50 role (Bruin and non-Bruin). Triffid was introduced after the requirement for an airportable force "disappeared" so were never put into trailers. The construction of the Triffid would probably make it difficult to put into a trailer.I've never come across a repair trailer, and the only C50 non-Bruin (ie without an RFA13 but with CST1+4 No3) I've ever seen is in Blandford.
The role of the TA units was to provide a line of communication from the Channel ports to connect into 1 (BR) Corps logistics train - and thus into 16 Signal Regt -hence the C41s.
In detail-
C50 (Bruin) 2 sets each with - C50, R236, RFA13, PSU49, PSU50, Frequency Synthesiser set, BID200/10
C50 (Non-Bruin) 2 sets each with - C50, R236, Frequency Symthesiser set, CST1+4 No3
C41 - 2 sets each with - C41 , R222, associated PSUs, CST1+4 No3
In the last picture, the box on the extreme top left contained the lighting kit.Also in the C50 (Bruin) version, a loadout deviation was not permitted. The RFA13 had to be nearest to the drawbar due to weight considerations. Some idiot built the system up the WRONG way around, and the trailer started swinging like mad, and nearly got written off!