[BenWA]

Thanks for the helpful link. I will build one of those soon.

I had the 7Y4 tube tested by someone with a proper tester... and it is bad in every way possible. Just like my multimeter showed, it was shorted out across ALL operable pins. (1, 3, 6, 7, 8). It was completely fried. That is more likely the problem. It was just a 73 year old tube (Philco brand! probably original!) that finally bit the dust.

All the rest of the tubes are tested good, although the two 7B7 tubes are weak (in the "?" area on his tester) and could go out next.

He had a Zenith brand 7A4 for $2.75 so I got it. It tested good on the same tube tester right after mine tested bad.

I am going to replace the speaker wires at the very least before I power it up again. The insulation is almost entirely gone in sections. That can't be healthy for it.

All the paper caps have already been replaced. Are these the electrolytic caps? (The ones circled in the attached pic)

EDIT: The round one you see in the back IS an old Zenith electrolytic capacitor... BUT upon further inspection, it's no longer connected to anything. Makes sense since there are large capacitors right under it (when the chassis is sitting upright) so it has been bypassed with modern caps, but left intact for appearances, I guess.