What would be a good replacement fixture? Mine was replaced with a modern GE fixture that got along at 100 volts at some point in the past but it's dead.
120v fixtures should work fine hooked up to 100v. I don't think there is and difference. I have a 120v fixture in my playchoice cabinet (was a JR).
If you want the original fixture put a wanted thread on KLOV. If you really want a 100v fixture but don't care if it is original I would say buy an under the cabinet light for Japan. But I don't think there is any difference. I think the fixtures in stores here even say on them they will work with 100v.
Edit:
I just checked on a few under the cabinet florescent fixtures and they all say they run on 100V-240V AC. So there isn't any difference.