[Arran]

I think that these sets, as with most Philcos from the mid 1930s used a cloth wire with push back insulation for hook up wiring, it doesn't normally go bad unless the set has been stored improperly, or it has been exposed to UV light, which is unlikely under the chassis. The same can't be said about the speaker cable, in a table set those are often exposed to tube heat, and sometimes UV light as well, plus they are handled much more often then the hookup wire.
  I know that this is about restoring the electrical part of your set but I suspect that your cabinet was refinished some time before you bought it, even though they did add a Philco decal above the dial. The reason I think this is because of the uniform reddish colour in the finish from a gel stain, even on the moldings, and it also looks like whomever refinished it stripped the filler out of the wood grain so it no longer has that glossy burnished look it would have had. They used to call this the "Antique Mall" finish as dealers in antique malls used to do strip N' clearcoats  to any furniture they had that had a beat up finish, some didn't even go that far and just rubbed the thing with tung oil giving it a dull blotchy look.
Regards
Arran