Outside lock with engraved buttflask.
With thanks to Sean Campbell, imaging manager of the Buffalo Bill Centre of the West in Cody, Wyoming, for permission to post these pics of a gun held in the Cody Firearms Museum. The blurb accompanying this gun follows.
If this date were accurate, it would rival the first ever airgun known (in Copenhagen) for antiquity. The word 'anno' may have been used in the sense of commemoration, which would explain nicely why it's there, while the gun seems more recent. Just what it would be commemorating in 1572 is anyone's guess?
Accession Number: 1988.8.4030
Inscription: left side of butt: ANNO 1572; right side of butt: WR - BS - KSH
Synopsis: firearm- airgun- left side of butt: ANNO 1572; right side of butt: WR - BS - KSH