I am sort of curious why you or anyone cares.
I don't mind answering that one.
I care because I have been looking at a Colt National Match from 1968 which is described as being 100% original and NIB. The magazine with the gun just didn't strike me as being the corrrect one, so I thought I would check with some of the more knowledgeable people on here. The answer that I got from
flintsghost was exactly what I was looking for.
The knowledge and expertise which forum members here are willing to share is invaluable, IMO.