Hi. The purpose of this post is to point out that you don't need to spend a ton of money on a brand new coin door in order to have a nice new looking coin door.
My cab is a used one from the early 80's. The coin door is your standard single door style (same as used by Midway). There are two metal coin slots and two round style push-in coin reject buttons.
The door looked pretty good, but had knicks all over (with rust in the knicks of course). The metal coin slots and reject buttons looked pretty ugly, since they were all tarnished. And then there were stains and gunk here and there.
So,
first thing I did was take it all apart. There isn't that much to a coin door, so remembering what is what shouldn't be too big of a problem.
Step 2, wash everything that's obviously dirty, with a wet cloth. I of course put more emphasis on parts that end up being visible. The two plastic inserts that say "25c" looked brand new after the dirt and gunk was washed off.
Step 3: Having cleaned off the dirt, it was already looking much better. Next was the the knicks and rust. This door in particular wasn't that bad, so it didn't merit a complete re-painting, but that certainly is an option for making a coin door look new. What I did do was paint the knicks and rust spots with a small brush and satin black paint. While the paint isn't a perfect match, it's barely noticeable.
Step 4: Last step I took made the biggest difference. We all like shiny things, and the metal on these old doors get really tarnished. I've recently discovered the joys of wheel rim polish. I used them on some aluminum Atari volcano buttons, to great effect. So I pulled it out for this. I used them on the coin inserts and on the coin return buttons. They now SHINE! Makes the whole door look near-brand new.
I'd post pics but I don't have "before" shots, and photos can't do justice.

~Ray B.