It being a replica of a 1940's knife,,maybe that long slender piece was originally a hook to pull separated hulls from the chamber of your SxS or O/U.
Paper hulls were all that were made back then and till the mid 60's.

They hold up fine. But will separate at the juncture of the brass and the paper hull quite easily after a reload or two especially if used in an Ejector gun. The hull can stick and the ejector snaps the brass head off and clear of the bbl's

Not much need for that hook on the tip anymore. Plastic hulls are quite reliable.

Maybe they just kept the long slender form and eliminated the functioning hook at the tip.

Just a guess of course.