I have a similar issue with a 630 TS horizontal sync pulse getting lost before going to the oscillator.
Been sitting for months waiting for a fix after complete recap.
I'm working on it for another VK member who has a Philco 65 roundie for me as compensation.
First step is to check your work, one cap off by factor of 10 or to wrong spot can cause mayhem and we all have done it.
Synchro-guide is explained in RCA literature (can supply some if needed) and re-reading it may help both of us.
I'm enlightened by Wayne's last comment above; grounding a feedback loop can give a clue if oscillator itself has good output waveshape, part of adjustment procedure noted. (have a scope?) This may help uncover source of unstable operation.