My father brought one of these for me from the US in the mid 1960s. Looked like a traditional side by side with double triggers, but child sized. The magazine tubes unscrewed for the muzzle end, or may have been bayonet fittings, long time since I saw it! Each side held 20 BBs, breaking the gun cocked both sides and gave two shots, one from each side. Very low powered, swapped it for something else years ago.
Now Wish I hadn't !
There was a thread on air shotguns recently, seems shot loads are ok, but they can also fire solid balls, which put them in FAC territory!
HTH David