opoefc - These are factory grips. These guns were offered with either round butt grips which were standard or square-butt extension grips, which are uncommon. Not everybody had small hands.

The third screw your are referring to near the top is not original. Somebody in the past has crudely drilled and added brass insert/nut and a screw. The parts DO NOT match the other two screws and brass insert/nut in the grips. I have had these grips off of the gun and I know. The brass insert and nut just fall out because they are not original. They are not even anchored in properly or fitted right. It is something I need to fix later on. The screw that is in there is actually too long and sticks out past the grips into my hand.

It would appear that the grips might have been loose in the past and that was just someone's quick fix. I did notice when I had them off is that the center of each one is bowed in, probably due to over tightening. Worst case scenerio I could always find anoth set of grips for it.