Thanks chaps, planning ahead for a potential purchase but it is sans rear sight…. Being hopeful
Original FWB diopter sights and FWB-compatible ones like the Anschutz diopters do come up on eGun.de or the cheapo Gamo/FWB-copy diopters fit the 300s. You could ask in the target shooting section on here if anyone has one for sale.
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.