Took me a while to get back to this, as I have been diverted by all the pleasantries of the fallout from my divorce.
Anyhoo, did some more inspection and thinking. The frame holes for the slide stop are oversized [or the slide stop pin is undersized] enough for the slop in the fit to allow the portion of the slide stop that engages the mag follower to back out of contact. This leaves the arm out of parallel to to the frame. I can push it into proper contact easily, but it does not stay there.
I am thinking that bending the arm as suggested above by PPC Shooter will cure the lack of contact with the mag follower, but will move any friction and stress between the pin and frame holes to a limited part of the circumference.
Queries:
Does my thinking about causation seem logical?
Am I overlooking some down side or unintended consequences of the proposed fix?
TIA
and holes