[Arran]

 The only sort of capacitors that would have used PCBs would have been oil filled capacitors, and most of those were used in motor run or motor start applications. What's more, as I understand it, PCBs didn't exist before the war, and even if it did oil filled capacitors cost at least twice as much per unit then your garden variety wax paper cap made by Sprague, Aerovox, or Cornell Dubilier, for example. In mass production costs matter, if they could trim 1/2 a cent per unit by buying one type of cap over another they would because those 1/2 cents very quickly add up to 100s of dollars in the scale that Philco produced radios.
  The insulation on the wiring was more then adequate for it's purpose when these sets were new, and probably for the bulk of their service life. The expectation, from market research in the 1930s and 40s, was that it was very rare for someone to keep a set in service for more then 15 years, certainly there was no expectation of anyone keeping one going for longer then 20. What sort of slanted things in favor of people like me, who happen to like early AC sets from the late 1920s through mid 1930s, was the war, because of shortages of many of the newer types of tubes beasts like Philco 96s and Atwater Kent 60s were kept around longer then they otherwise would have.
  As for the asbestos some radios had, it was quite common in Canada at least for the manufacturers to staple a sheet of asbestos paper to the chassis shelf inside the cabinet, some did this some used a steel plate, this was in wood cabinet sets of course. As for it being a health hazard, not likely, the variety of asbestos they used was chrysotile asbestos, the white kind, which was among the most benign, the ones that got sick from it were primarily men that worked in mines that received a very high exposure. Curiously in Great Britain chrysotile asbestos is considered a form of talc and a moderate health hazard, mainly because they didn't have class action injury lawyers and clean up contractors fanning the hysteria to make themselves millionaires. Now they are making the same pitch with mold. Given the non stop commercials that they run on some channels looking for mesothelioma victims I have to think that the well must be running dry by now since it was banned from the market in 1979, but the lawyers have to get their cut of the trust fun monies somehow.
  The hysteria surrounding lead is just baffling, lead is everywhere, they used it in the millions of pounds, as an anti knock additive in gasoline for decades. It was also used in paint, I can understand the potential problems in children eating lead paint if it is flaking, but it's pretty cut and dry as to how to deal with it. I never did understand the impetus with banning lead based solder being used in electronics, nobody eats electronics, and it's very unlikely that a child or anyone else would have occasion to lick the traces on a printed circuit board. I know that they banned lead based solder in Europe, that's where that RoHS garbage came from, but they are two faced about it, lead free solder is actually banned in three areas over there medical, aviation, and military equipment, because of tin whiskers of course. As Mike suggested, there is lead in rocks, lead in the soil, the idea that lead "contamination" is leaching from junk TV sets and radios is absolutely laughable.
 Of course knowing the way business operates in certain Asian countries they probably label things as being RoHS compliant and use lead based solder in it anyhow. Which is also how they sidestep any questions about how things like I-Phones and solar panels are made.
Regards
Arrab