It's not a Midway coin door. It's the same door manufacturer though. Midway logo plaques are made of metal and are "bolted" on. If it was painted over, you'd see a black rectangle. If it was removed, you'd see two small holes where it used to be.
By the way, were there any "hints" to the cab's origin inside? Stickers? (check bottom of cab, sometimes with age stickers dry up and fall off...). My cab (which looks like yours but is wood-grain) had a "made in canada" sticker as well as a manufacturer sticker for some company in Ottawa, Canada. The monitor, oddly enough , has Williams stickers on it.
Anyways...... As stated already, seems safe to MAME.
OH, ps: Is the control panel hinged with a piano hinge on the front? Is it wood or metal?