I got tired of refinishing the cabinet for now, so I'm moving on to trying to figure out why the sync sep circuit is unstable. Set works pretty well, but it randomly looses sync at times.

Finish on that cabinet is dee-licious.

Lookin' good :thmbsp:
Is it loosing horizontal or vertical sync ?

It's bad horizontally, and the hold control is very sensitive. After it's been on for a little bit, it starts tearing horizontally and the hold control won't bring it back. There's still a few micamold caps in there, so I should probably get the remaining few.

Definitely replace the micamold paper caps masquerading as micas. If you do replace the two mica caps in the horizontal output (680pF & 900pF), make sure you use 1000v mica caps.

I have a 560 @ 1kv I could use in place of the 680, but the closest thing I have to 900 would be .001uf @ 600vdc. How critical do you think those 2 caps are?

I think they're fairly critical, but you might as well give it a try. I used a 910 pF mica cap.