I have an old Colt Cobra that was pretty beat up when I bought it from a retired detective. I sent it to Cylinder and Slide in Fremont, Nebraska, and asked them to do an an action job and refinish it.
I wanted a dark, durable finish that wasn't slippery, so I chose an in-house finish they call Cerami-Cote Black Satin Graphite. I'm really happy with it.
When I first called them, their president, Bill Laughridge took the time to speak with me about the choices for refinishing an alloy revolver. Cylinder and Slide is a first-rate operation, and I plan on using them again for any revolver work I need.