That's just sad. I hope the guy sells the original parts and doesn't assume they're worthless and toss them out.
My Gravitar was in worse shape when I bought it. It had been converted to Street Fighter III. I was the right buyer who had enough original parts to bring it back. I didn't even really want a Gravitar at the time but I couldn't leave such a nice cab in that condition. Now it's all the way back to being a real Gravitar. My point is that someone might get their hands on that Space Duel at some point and put it back together. It's not game over... well maybe, but necessarily.
Bill B.