Uy that comment about the varistor gave me pause! There are two other similar components in the set, so I suppose it could have gone either way. So I pulled that sucker out and:
https://i.imgur.com/vPQQIMs.jpg
1800pf capacitor it is (or was).
It's connected to pin 6 of the PCF802, which the RCA handbook tells me usually runs with 100V on the plate. I have a huge box of those cheap-o capacitors and found a 1500 at 630V, put it in there, and it's running now with a great picture.
Thanks everyone!