Think you’ve seen it all? Then take a look at this 12 gauge Beretta Sparviere over-under double barrel shotgun. I’m not sure why why you would want the locks to do this, but it is pretty really ‘friggin cool.
I’m pretty sure the Bertuzzi Bros. invented the gullwing design. Elio and Remigio used it on a handful of their finest SxS shotguns (like this 20 gauge at CSMC), and they may have also added it to some O/Us. Their design functioned the same way, but they mounted the lockwork on a plate inside of the action.