Thanks for the info everyone! I do have one question for you though @UNPROFOR1994. You mention that:

It isn't cut, it is the normal early Model 1892 type, later you also had a curved and straight one.
Do you mean that some just didn't have a stacking pin? Cause as you can see in this close shot:



There is the nub where it ought to project from, but it just isn't there, hence why I suspected it had been cut off.