Snap on tools has used spring loaded ball retention ratchets and extensions since day one in the 20s. Snap On was the first tool manufacturing company to have the interchangeable socket and handle design. After a period of use the ball would wear factory swaging that held ball and spring in tool would come out. They came up with this punch so tools could be repaired in the field. Dealers kept repair kits and fixed tools on spot. Ball and spring were replaced and held down firm on an anvil and with a couple of sharp blows and tool was ready for use. In the 40s snap On was Drafted to produce tools for military WWII and with that started using alloys to harden tools. This helped on wear and less retention ball replacement. Tools like this were used from 20s-70s as snap On furthered use of alloys to extend the wear life of tools. This punch is a second generation A model . By the mid 60s snap On was forced to build very thin tools for the navy that would get in tight places that would hold up and not crack.This brought on the alloy Boron for hardening. With boron being added steel hardness has greatly improved tool quality and stopped the need of retention balls and springs replacement. Swaging punches were kept in parts bins on trucks until early 80s G671A was shown discontinued by SNAP ON in 2005. The G671A punch was last in Snap On's Computer system in 2005 as discontinued with no pricing ( Don't know how many years it was there as disc. Before being dropped off. During this time Snap On started up it new Chrome Computer software and items didn't carry forward)Tool was listed as an embosser. Couldn't find in snap on catalogs for it was a Dealer use item from all I can find.