Problem solved.
One of the first things I did over a week ago was replace the dud HV rect with a NOS one that tested good...
Today I tried running the set with the Reg pulled, but ONLY it's heater connected, jumpering the HV reg cathode diodes, and shorting the ground side HV pot resistor along with component testing and verifying osc drive. wave forms.
When all that was normal, and I could get a beefier arc off the flyback lead to the rect than the HV connector I decided to re-check the new rect tube I installed last week...It was dead. I grabbed a weak rect. in the bag of original parts changed since I've owned the set and got full 25KV.
It was rather unexpected that a NOS part would test fine and rapidly die like that...Glad it is working again.
