[Kelly Carlson]

Very attractive, Coop. I like the way you dressed up the screw holes. The soft two-tone coloration of the metal adds nice visual interest.
With the slighter thicker liners of the GPC & GX, the detent ball doesn't need any relief on the frame/bolster side, but I think that continueing to provide a bit of relief on that side does result in slightly smoother operation.
To respond on the lock treatment question:
On some of the DDR's the detent ball protruded slightly on the outside of the spring, resulting in additional resistance when opening as a result of pressing against the bolster. Providing relief on that side eliminates that resistance and facilitates a nice, smooth action.