[Arran]

I can't really answer that question for certain but if the cloth wire is used on something like a power transformer it may be because the transformer came from an outside supplier. Maybe the lower voltage wiring was rubber covered and the high voltage cloth? Perhaps the stuff that was exposed like grid caps, pilot lamp sockets, and speaker cables got the cloth wire and only the hookup wire inside the chassis was rubber? in any event I replace the rubber crap with vinyl insulated wire, the closest modern equivalent, why pay extra for repro cloth wire when the set didn't use cloth in the first place?
Regards
Arran

P.S Be thankful that most U.S manufacturers didn't start playing with rubber wire until 1939, I have a Rogers Ten-60 currently on the bench that used that crap and it's from 1936. It also used hand wired circuit boards to mount many of the resistors and paper capacitors to, which was connected to the rest of the set with rotting rubber wire, among other delights.