My honest opinion: It's not a Tron. It's just a "Midway" mini. That same style was used for Ms Pac, Omega Race, and a few others. So really... why bother with the pain of reassembling parts. Just keep looking for a complete one (or completer).
But what makes it a Tron in its current state? I guess that was my point. It could just as well have been a Ms Pac converted to Trivia Whiz. (Encryptor, you didn't say so explicitly, but the original boards and wiring are still in there??)
That was the first question I asked before buying. How do you know it's a Tron. The guy I bought it from said he had listed it as a mini Ms Pac at first and got a bunch of emails telling him it wasn't a Ms Pac but a Tron so he opened up the back and the labels in the pics below are inside the back door.
I can't say positively but it looks like the wiring is there tie wrapped up. I know the cp is original because when you look underneath you can see the mounting bolts and holes for the joystick and spinner.
I bought this because it's a mini and they're just aren't that many of them around. Tron is probably my favorite game of all time. I've seen very few Tron cabs of any kind in my area and the ones I have seen have gone for $600+.
That's a good question. I'm assuming -- correctly or incorrectly -- that at least some of the guts are there?
I can't help looking at that cp and thinking of all the bondo work ahead. 
There won't be that much bondo on the cp. When I get around to doing the cp I'm going to have the holes that are there for the Trivia Whiz buttons welded up. I'll just have to grind them smooth and put a skim coat of bondo on.
Bottom line is that it is a Tron mini and I thought the price ($150) was decent for a cab that you don't see that many of. I check ebay and craigslist a dozen times a day and I just don't see mini's there.
Encryptor