Don't think i have ever seen a 121 and i have almost every airgun world, well all the early one's. Were they on sale in the uk, and who sold them.
See post #3. They were aimed at the German market, which had a lower maximum power limit than the UK, so probably very few, if any, made their way here in the '70s.
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.