Now I am planning on converting this over to a Donkey Kong machine via Mame. Got the new Marquee coming from emdkay. Got the plexi cut at lowes.
Don't do it, please. First of all you are destroying a very nice dedicated R-Type cab. That's a real shame. And destroying the side art is an act of crime!
With a bit of TLC this coud be a very nice cab (it's already in pretty good condition), and whatever is wrong technically can be repaired. R-Type is one of the best SHMUP's ever, and it is a true classic.
Secondly, wahtever you do with the cab to turn it into Donkey Kong, it will be rediculous because it is no Nintendo DK cab. The shape isn't good, the color is wrong (or are you going to paint it? Not that it matters because it still will be rediculous) and there will be Mame in it (I'm sure that at a certain point you will have all kind of games running in it which makes it .... well, an ordinary Mame cab).
Please reconsider this, it's not too late. You can buy a generic cab for verry little and turn it into a 'Donkey Kong Mame cab'.
If I would live in the US I would buy the cab without thinking from you, even for double the amount.