I had an old Belgian folder, great gun, rabbits hated it! Back in the day we weren’t blesssed with large wax cotton Barbour coats with a “Poaching” pocket inside which you mentioned , we had to use ex army great coats and if you brought enough rabbits home your mother would sew you a “Gun” pocket on the inside. We also used get roosting Pheasants with catapults, but that’s another story for another time.
The first shotgun I ever fired as a teenager was my Grandfather's old Belgian hammer folding .410. 30 years later and I just inherited it last month. It means a lot to have it in my cabinet. Will be bringing it to the Oxford Gun Company in the next few weeks for an outing.
The problem with .410 is the cartridge cost. It’s a very expensive way to shoot vermin, especially as you can buy very good 21gram 12 bore loads for a fraction of the price. And loading your own is more bother than it’s worth?
I had the accio version, with the conventional top lever it was far superior than external trigger or lever type. Shoot .410 quite regularly now with a double barrel Yildiz as do quite a few others do in our clay team, brilliant fun.
I've got one for dealing with squirrels. Old, and of unknown make. 2" chambered !. My first gun was a 0.410 my Dad bought from the London Army and Navy Stores. I was sent straight off to the Churchill Shooting ground to be taught gun safety before being allowed to shoot it.
Cogswell & Harrison used to market a neat example. Doubles were also made by the Belgians and Spaniards. There was also an Italian made folding 12 bore. I have had them through my hands from time to time but now only own a .410 re-bored single rook rifle but not a folder.
I used to shoot the folding Spanish side by side Winchester x 3inch cartidges with similar folding mench but with double hammer. Lots of bunnies for me and ferret.