About four or five years ago I sent M64-3 in for a complete overhaul and the Master action package. The gun came back like new along with a bag full of old parts and springs. I'm sure it was done by one of the old school gunsmiths as small touches of "pride in work" were done to the gun. The top rib on the barrel had some shiny spots from holster wear and was refinished dull. Also the trigger which was originally ribbed was replaced with a current, smooth combat style. He's probably retired now. Whoever the tech was, he did a fantastic job and the action is like absolute butter. It is so nice that I only shoot it double action. I decided to swap out the original hammer double action sear onto a Factory bobbed hammer and have never looked back.
Klyde