[TV MAN]

RodB is dead on putting caps in series if you need higher voltages,. Many OEM setups are already that way esp in doubler circuits and amps that use higher than 500v in the B+. The ceramic HV caps should be ok, but if you do end up needing something, Just radios (Canada) has a lot of HV caps. Both tubular and disc. I've used them in restoring electrostatic sets. Just remember, take lots of close pictures, notes and I really urge you on doing a section at a time - test, then move on. Also, I don't remember if I mentioned leaving the brightness down when you test in case the vertical is dead so you don't burn a line across your picture tube. Sneak it up very carefully and listen too since you can hear the vertical running (or not). You may also be able to hear the horizontal section start up, although some people cannot hear it.  If in doubt about something, you can snap a picture of the section of the schematic in question, and post, such as the power supply or horizontal sweep section.