Here's a peek at the inside.
I really hope these are originals and not an ugly repair job.
There's the 7F8 up towards the front. Later sets used a 12AT7.
Ah, those caps do appear on the tube chart so I bet they are original.
Weird. The earliest schematic I could dig up is the the TS-4B and it doesn't have these.
That's all for now. I'll try to find time tomorrow to pop the chassis out and test the 7JP4.