well, it is later than 1820s mfg. The 12 g shell was created in the 1860s (before that, muzzleloaders).
Twist steel indicates a black powder shotgun, so likely prior to 1898. Do not recognize the name, but many of these WERE made in Belgium. Or at least barrels made there, assembled here.
Remove the forearm, take barrels off, look at the water table for marks. Use slanted lighting- hard to see.
What we have here is... failure- to communicate.