Took John's advice, ended up with a Coline 40Kv probe (model HV40B) from Ebay for around $70. Nice unit, even has spring loaded covers that slide over the terminals when it's unplugged. I was able to verify that I have a solid 19.5Kv coming out of the HV rectifier, and the regulator looks like it's doing it's job as well. But another problem surfaced: if I tried to get the picture into focus, all I got was some very pissed off sounding arcing and a bad smell...
Focus pot appears to have bought the farm, probably as a result of years of wear or maybe the old convergence transformer taking a dump. As predicted by John, it only arced when near the high potential side of the pot. On visual inspection there is a good big of gouging in the carbon element, it only reads 3.2 meg now vice the 5 meg it should be according to the schematic. Once it's replaced I should be able to get a decent picture on the screen, so off to the interwebs I go in search of a new one.
