I love your idea up to a point. I grew up playing these machines, and NONE of them were nice. Scratches, cigarette burns, and joysticks on their last legs were all the norm. I prefer a converted cab with dedicated art to a homebuilt with a cartooney control panel overlay and art from 30 different machines, but I'm sure that I'm way in the minority.
The thing is, once you get it inside and it starts stinking up the place it's a hassle to get it back out and make it right.
I suggest sanding and painting it (cheap, just hit it with 220 grit and roll it with satin black enamel and a foam roller, supplies will be around $25) and putting in new sticks buttons. The controls are key to the experience, and they're also not that expensive.
Just so you know I'm coming from the EXACT same place as you, here's my beater Twin Eagle in a Zaxxon cab.
Its gone to a new home, but this machine had a lot of charisma.

