I know nothing about the history of this TV, so multiple problems are
a possibility. After power-cycling, it ran fine for long enough that I
actually got tired of watching TV. My next guess, on the "total loss
of convergence" problem, is one of the four electrolytic capacitors in
front of the IC. They're cheap enough that I'm just going to replace
all four. I believe, however, that the "red image is bigger" issue is
a second, unrelated problem? Possibly even more mechanical than
electrical? I definitely need some guidance on this one.

Is the red image "smeared"? If so, check the electrolytic caps on video
drivers.