Six years ago I sent them 16 ga. M-21 for correct and documented "Win. Custom Shop" rebluing, changing pistol to straight grip, and a custom splinter forend. Spoke with Tony on the phone as he examined the gun, got a written quote, and said "go". The gun came back wrong in more ways than I want to detail, and it had to go back 3 or 4 times because when the guy working on it corrected one thing, he damaged or otherwise screwed up something else. The worst was getting it back after barrel rebluing with the right barrel way off face, left one tight to the breech. Eventually they would no longer return my calls and I sent the gun to Andy W., who did good in repolishing/rebluing a poorly polished frame, and refitting the bolt to restore the takeup screw's function after they put the barrels back on face.
I expected to never do business with CSMC again, but as the reports of RBL finish quality became consistently positive, I broke down and ordered one - thinking they might care more about fixing one of their own guns if there was a problem. I did send it back to fix a minor barrel finish problem and a sticky bolt. I can't ask for anything more in customer service than I got from Adam, who assured me they'd take care of the problems and promptly did.
Jay