[Ron Ramirez]

You can buy from Remington direct, bypassing eBay:

https://www.remingtonindustries.com/

Be aware they do not carry 20 gauge solid wire with UL1015 (600 volt rated) insulation, only stranded. Solid wire is what Philco used originally. In fact I have not been able to find any supplier for good 600 volt rated 20 gauge solid wire. Solid wire is easier to work with when you are replacing multiple wires under the chassis and will stay in place better (far less likely to want to curl up as stranded wire does). Plus, 600 volt rated 20 gauge solid wire more closely resembles the original rubber-covered wire.

Antique Electronic Supply carries 22 gauge, 600 volt rated solid wire. 22 gauge will work for the 1939-42 Philcos.

I used to unsolder one end of a rubber-covered wire, remove the crumbling insulation, then slip heat shrink tubing over one end, heat the tubing to shrink it, and reconnect. However, over the years, I found that it was just as easy to replace the wires rather than resleeve.