I've got the above book for sale in the main air gun section, titled 'various stuff' it's from 1979 and the valuations are eye watering! I used to see Dennis in Jeans Military shop in Great hardwood, is he still alive? used to love his sales catalogue, very schoolboy.
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.