Top row, 2nd from left:
Haven't ID'd it yet but it looks very much like a Pistol Hammer or possibly a Shotgun Hammer. But IDK

IF....... You want to wander thru over 29,000+ Percussion Auctions with pictures to see if you see a match I found this listing where I believe all were listed by Auction houses in Englandicon.
Put a pot of coffee on and scroll away !

Link: https://www.the-saleroom.com/en-gb/p...ide/percussion