Responses have been inlined.

Do you have ny video test equipment?

I have a working color bar generator that I've fed into the unit. (I've
found that it's just barely possible to get stable and correct color with
the bars by tweaking the trimmer in the color oscillator circuit of the
character generator.)

As far as a vectorscope goes, no, I don't have one. It was brought to my
attention elsewhere that I could use a VirtualDub plugin and video capture
card to provide a vectorscope in software. I'm not sure if I'd understand
how to use it. Nor do I know if it would be accurate (enough).

I may try a new crystal and make the effort to replace electrolyic
capacitors at some point in the future. Right now I've set it aside as I'm
tired of fiddling with it and have no pressing need for it to work.

William