1968 Zenith 20Y1C50 chassis - advice needed

[joe111671]

Hello again everyone. I have this all metal Zenith from an estate sale. When I got it over a year ago, I powered it up at the sale and it made some dim fuzzy snow, but was making quite a bit of HV snapping sounds. After taking the cover off, I could see why. It had years of dust in it, thankfully it was not in a heavy smoker's home. I cleaned most of it out, and that took care of the snapping.

When I power it up, and the picture just starts coming up, it has good focus for a split second, then goes out of focus and is out of range of the adjustment. It also has a rainbow colored field moving slowly up the screen, it's almost like the degausser is stuck on, or it needs the main filter caps.