Here's a Stainless GP-100 MC in 10mm auto, that came in for a Python hammer. Since the actual making of the hammer is detailed elsewhere on this blog, I won't get into all of that here. Aside from the inletting of the grip to gain clearance for the hammer spur, it's just like the other GP conversions.
Let's compare the fit of the double-action sear between the factory part and mine. In the factory hammer, the pocket for the DA sear is created during the casting process.
Since the new hammer is hand made, from an O1 billet, this problem (among others) is corrected.