[Yamamaya42]

Odd behavior with brightness / contrast localized.
Power supply seems to be acting up a bit, it's NOT the pair of 5U4GB tubes, tried new, no change.
Have noticed slight changes in brightness / contrast as the set is in operation, could not work out the cause, then noticed that the horizontal width would change in relation to the sound when vol was up high, pulled the 6K6GT audio output to try another I had, brightness / contrast came up substantially, tube swap made no change.
Working much better with audio output removed, possible sign that the bleeder resistor network which is still original save for 1 section is starting to fail.
However, not willing to pull it apart just yet, as this chassis originally did not have audio output to start with, I'm going to use a band-aid method to keep it going till I'm ready to work on it again, at which time I'll also attempt to do a IF alignment, which it really needs.

So, in the meantime, remove the audio output and use a cheap ext class D amp.