I'm totally unfamiliar with this system, and would be interested in knowing more about it. I'm surmising that this gun is a percussion shotgun that is loaded from the breech end.
If this is correct, then I am curious how effective it was at containing pressure and protecting the shooter from powder gasses when firing. And does it toggle over center as a means of bolting? Nothing else seems evident from the pic. It certainly is well preserved considering its' age, and an unusual example of firearms evolution.
