Info: I again lightly (1000 grit) smoothed the area under the rear of the sight.
I also used 1000 grit very lightly on the sight's dovetail. I didn't remove the black coating, just dulled it a little. I sprayed both with CLP.
I tapped the sight in with an oak dowel and mallet. It went in snugly but very smoothly--it took much more than that last time. I mushroomed the dowel with firm, but not massive taps.
Light can be clearly seen under the sight all the way to the dovetail.
There is no stress on the sight. I'm the only one with stress.
I have to zero it-maybe today. Sincere thanks to all who tried to help.
Don
