RayB, great suggestions!
You can buy new control panels can't you for a Ms Pac? One with the holes punched to your specs? Arcadecabinets.com?
Super Pacs are getting more rare. Lots of parts for them though. And cheap for now.
I saw one sell at the auction working last weekend for about $240.
Yes, you are supposed to have the blue speckles on the machine.
No, I wouldn't change it to jamma if you don't have to. To the pure collector, I think it makes a difference. It does to me anyway.
If the cab is in good shape, has the original power supply and hasn't been cut or torn on the sides, I'd say restore it. However, if it's been hacked up and cut up and it doesn't have say 70% of the original brackets, markings, etc. To me it's a candidate for Mame or conversion.
Pac are usually in pretty good shape. But Stargates, well, they are converted to junk everywhere.