[old_tv_nut]

If you turn up contrast just to where it does bleed, and then turn brightness way down, does it go away?

I don't know, but it's possible it has a beam current limiter that works to turn down contrast as you turn up brightness, and that's why the brightness can't cause smearing. Or it could be something else peculiar to this chassis that I can't think of.

Anyway, the red smearing is most often an indication that the red video output stage is saturating (going to the lowest possible output voltage), often due to the setup voltages required with a tired tube.