I spend a lot of time in the retro forum. There's a place called victor's anodizing which has always had superb results from the pictures I've seen. Plus, you have the choice of color. Of course, that's only for fubar receivers, not steel parts.
You're probably talking about Victor "with" U.S. Anodizing.
Here's a sample of some of his work that he's done for me.
Note: Just the lower was refinished. It matches up really well with the factory Colt LE6933 upper doesn't it?