I have a pre 10 (C - 80xxx) that is missing the thumb piece and screw. Sounds simple....NOT! I tried one meant for a Combat Masterpiece. It wouldn't fit the slot. Then I found one that was advertised as being for a pre 10. It fit into the frame perfectly. But, it won't allow the cylinder to open or close and locks up the action. It does the same thing in a few other pre 10s I tried. As a control group, I switched thumbpieces between the other guns & the one w/ the missing part ..... no problem. So, why does my replacement fit and then freeze the action on each gun I tried?
The obvious answer is to return it and keep searching. How difficult would it be to alter it to fit?? What area on the thumbpiece would be the likely problem?
The top thumbpiece is the one ,taken from another gun, that fits several of mine including the needy one. The lower is replacement that won't function.