They were made in several patents of action types, by at least three mfgs, with grades from Farmer to King. Once the InterNet forums got rolling, it didn't take too long for them to start climbing in value. Lots of WWTwice bring-backs in NW Ohio farmer country -- where a 16ga double was the Coolest pheasant gun.

They are also, light, have 2 5/8" chambers, are bored tightly, choked even tighter[generally], and kick viciously with High Brass Long Range Kill'um Dead loads.

Fortunately, the years and BBS's have done to educate the interested shooting public, and so I would count myself fortunate were I to own one.