I agree with Chadtower. Definately use a decased 19" CRT PC monitor....if your converting to Mame.
Arcadeshop Amusements have Space Duel CPO's. Quartercade have a Space Duel CPO as well as 2 full control panels. One is in excellent condition (just needs a clean) It's populated.... but no cone's. The other is fairly crappy.... but populated WITH cones. May be a bit pricey.. so search around for original panels. IMO you definately want to stay original theme externally.. ie metal cpo.
From the sounds of Santoro's initial thread on this cab a while back, the sideart is not recoverable? Pity.
If needed, TNT Amusements have a Space Duel Marquee. Check out Bob Roberts for the buttons. Check ebay for the Atari Cone Switches/buttons and/or any other parts. In fact if you check ebay now...you'll find some nice stuff!

As for your coin door...if I'm reading it correctly...rewire it back up, when it's restored, and use it in the cab through Mame...
Good Luck.