Some blue masking tape if you must.
What are you doing that requires grips off and such that pins that are supposed to be a loose fit are falling out all the time?
Have in-stalled commander hammer. sear, springs, drop in gripsafety. I know they are not pretty, but I'm anticoagulated and suffer from hammer bite, Daleltaylor@att.net
The first thing to do is measure the diameter of the pins and the respective holes in the frame.
You may find you need oversized pins.
The pins should not be so loose that they just fall out. If they are that loose either the pins or the holes are out of spec.
Regards
Bob Hunter www.huntercustoms.com