[MrFixr55]

There does seem to be a lot of good work there. I especially like the fact that the filter caps are RTVed to the chassis. One thing to try is to verify that B+ on plates and screens of the IF tubes and plate voltages on the Osc and Mixer are somewhere where they belong. Please be careful of high voltage when doing this and the following steps! Try to touch the grid of each IF tube (through a capacitor to prevent or limit shock) to inject some hum. If you hear hum, static or clicks, that means that something is getting through the IF (yeah, an IF shouldn't pass 60Hz Hum but in a noisy environment with Romex cable, fluorescent lights, computers, etc... If nothing, ohm the IF transformers and replace the 6H6. It appears that it is both the FM Discriminator and AM Detector. There may also be an issue with the band switch. Unfortunately for the issue that you are having, a signal generator would be of great help. The IF on this set is 455Hz. If you have another radio with this IF Frequency, you can Frankenstein a signal generator or signal injector from it. Of course, if the Signal Injector set is an AC / DC AA5, then us an isolation Xformer.

The 2nd IF Output Xformer is rather interesting. It has to be because it is for both AM and FM. There are some capacitors in that can. Dunno if these get the dreaded SMD but when all else is exhausted.

Hope all of this helps.