Installed the recoated CRT and did all the ion trap, focus coil linearity etc adjustments again. It's playing well but still get the occasional arc in the CRT on power up. Will try an isolation type booster when it arrives in a couple days.
Meanwhile, the picture isn't quite as sharp as I think it could be so I'll try a video IF alignment. It used a staggered tuner IF and it's a an easy procedure. Feed an RF signal into the mixer tube shield an peak each coil to the specified frequency frequency.