OT for the thread, but very interesting re: cl.253 sets with the 2 catering vehicles, i.e. TRUK/TRSB
the way they're formed makes more sense too, in that the TRUK is next to 1st class, natch, but the TRSB is 'inside' the 2nd class part of the train, meaning most buffet customers were only 2 coaches at most from the buffet
of course, later on, these 'twins' would be ECML only with the catering cars together, meaning you potentially had quite a journey from the end TS/TGS to the buffet and back, trying not to spill your 'maxpax'!