How many Webley endcaps have you seen with the end plug slot chewed up? They put “do not remove” in red for a while? At one time they put a pin in it so it couldn’t be turned. Seen those screwed up as well. I just bought a 1925 Mark II Target and there is no end cap slot. Why did they get away from this? See pic.

https://i.imgur.com/dHVmX5X.jpg