Im pretty sure he said that the one on the gun had been made by somebody---I'll have to ask what happened?
I think with some of the older stuff that if a repair/ bodge had been done many years ago it is a part of the guns history and character.
I've seen worse bodges than this:
Vintage Airguns Gallery
..Above link posted with permission from Gareth W-B In British slang an anorak is a person who has a very strong interest in niche subjects.