So I bought a big-ass TV off Craig’s List, and he warned me it was 10 years old and the tubes hadn’t been replaced.  I stupidly bought it anyway.  It works, but not well.  It is a little dark, but that’s to be expected (with the old lamp).  But the bigger problem is the fact that anything that’s bright (whites and yellows) is radiantly bright, and anything darker than, say, a medium red, is almost invisible.  That and there’s a blue halo around everything.
I did a little research – I took it apart and will buy one of those cans of air and will try to clean off the lenses and so forth.  I will not buy replacement tubes because a) they are probably not even made anymore and b) it will cost a stupid amount to replace them.  But if this works, it’ll at least be a usable TV and not just a huge conversation piece.