I popped the back off this set and took a look inside. It appears to be in pretty good shape - nothing obviously blown.
Horizontal output tube looks dead.
This could be why

I see a few cracks in the old coating so I suspect this was a attempt to stop arcing.
I haven't tested it yet. Hopefully, it's still good under all that tape.
Now to test the CRT. I would have used my Sencore CR70, but I'm missing the #4 adapter
So I had to drag out my old B&K 440. The emissions came right up into the good range. The life test stinks though - even after an hour of running. Oh well, I'm sure it's good enough to produce a picture.