[Arran]

Buzz;
A few observations about the speaker, acetone and lacquer thinner are useful if you need to dissolve the glue holding the cone and gasket on the basket, and for getting the voice coil and spider separated. Also it's probably better to take the pole piece out of the rear bracket with a press rather then hammering it out, even an improvised press such as using a jack under a car frame, or part of the house, hammering can cause the ends to mushroom or flare out making them difficult to get back in. Also, unless there is a flange in one end of the pole piece preventing it, pressing it out from the rear rather then the front would have been less effort, like moving 1/4'' forward rather then the whole thing through the back. Also I would use a socket, or some other cylindrical object as a form for the voice coil, it's too easy for it to end up out of round. I think that reconing was the best option in this case as even a replacement from a scrap set would likely have the same issues with a crumbing cone, this being a Silvertone it was built to a price so they likely acquired their speakers from the cheapest supplier they could, and let's be honest nobody making radios in 1940 thought that these sets would still be around in 85 years, except maybe Mr. Scott.
Regards
Arran