Slide stop spring and trigger pin issue solved.
As I wrote before, the slide stop spring did not protrude through the frame on my Girsan allowing the trigger pin to back out some when shooting. Here is a pic of the issue.
I solved it by picking up a new Beretta spring from Midwest Gun Works. Arrived very quickly so I was pleased with their service. Ordered 3/13 and arrived today 3/16. Here is a pic comparing the old spring (bottom) and new spring. You can see that they are significantly different.
Installed the spring and everything functions correctly. The spring end protrudes as it should. No more trigger pin backing out.
My extra Mec-Gar Beretta mag should be here on Monday. I will get to the range again this coming week and let anyone interested know if it functions properly in the Grisan.