I have a side by side 12 ga. shotgun that appears to have been built by a F. W. Kessler in Germany.His name is on the right barrel and on the rib between the barrels on top is the name Carl Bock frankfurt a/M.It appears to be a quality gun with lots of engraving and a horn trigger guard. Can anyone give a me more information on this shotgun?

Thanks in advance for your help.