Electrical work has finally began with the smallest chassis - the self contained audio amp.
It has its own power supply and features a pair of 6F6 driving the single, big field coil speaker.
Started testing components and immediately ran into a problem - push-pull output transformer is open on one side of center tapped primary. Grr.
Easy enough to replace with something like a Stancor A-3823, but it won't look like the original.
Also discovered the original candohm resistors is gone and replace with three power resistors. I'll probably replace with three chassis mount power resistors.