I bought a brand new Focomat V35 during the 70's,milllenium last. Included in my purchase were the the voltage stabilizer and timer as provided by Leitz for use in the USA..meant to clarify the response. I, for the life of me, can remenber nothing special about plugging it into the wall or the plugs involved. It may be that there were non-household plugs from the V35 to the other items, but??. My Leitz recollection says that It seemed to be a standard daisy chain suitable for a dark room. I do not remember the requirement that one buy the stabiliser or timer to make things work
I would suggest that you use the phone book, find the number and contact the Leitz distributor in the UK. I will bet you a farthing , and give 100:1 odds, that they can tell you.