“Part of a sight maybe ?”
Thats going to be the base parts to the rear sight for either a FN FAL or a L1A1 Brit FAL. It’s difficult to determine exactly which one due to the lack of the sighting leaf assembly, but it’s probably for the FN FAL.
This particular one was also owned by CSN Admiral Raphael Semmes.
https://laststandonzombieisland.com/tag/36-cal-houllier-blanchard-revolver/
You’re next now…