New here and to Vintage TV.

[DaveWM]

focus can be a problem. On some of my sets it seems to be at an extreme end others is fine. On one I had to have the coil turned all the way in (coil used not a pot) and it was still soft, then replaced the focus tube and it was the other way. Same with deal with focus sticks. If you have a supply of focus tubes try subbing in others. Your setup sounds good, so try subbing the video out tube. The pic looks good, if it gets much brighter you will prob start to have some retrace line issues.