I've started making some progress on the set finally. I replaced a few open resistors and that one blown cap then took a closer look inside the HV cage.
Dusty!
That power resistor didn't look right to me - the original would have been much larger. Sure enough, it's open. It should be 8500 @ 25 watts.
I couldn't find one so put a 5600 and 3000 in series.
While it's open I also cleaned out the dust bunnies and found a 1Meg that was 30% high inline with the HV lead.