Gave it a coat of cold blue. Normally, I'd polish out the machining tool marks, but it'll all be hidden by the scope base.
Worked out the hole locations in the base to line up with the adapter and drilled away.
Flipped over, picked up the holes and counterbored.
Guess I took this pic before blueing the adapter. Anyway, here's all the related components.
Ahhhhh, there's the blued adapter. The adapter replaces the rear sight.
The scope base bolts to the adapter.
Blends in almost perfectly.
And, finally, the red dot is mounted nice and low to the bore axis. A few sighting shots later, it was dialed in. Should I ever need to add a picatinny rail to the pistol, it'll only take a few minutes to cut a piece to length and drill two holes. And in even far less time, the iron sight can be refit and the pistol returned to original condition.