info on an old SxS shotgun?

Anyone familiar with an old SxS hammerless 12 ga. marked "The Berkshire"? It has a five digit serial number visible on the receiver, the Damascus steel barrels and the inside of the forearm. It has very minimal engraving and looks to have originally had double beads, but the rear bead has been removed and plugged.

The only info I've found on a Berkshire shotgun says this was a trade name used by the H&D Folsom Arms Company on shotguns made for the Shapleigh Hardware Company. If this is so, was Folsom actually the manufacturer or just a distributor?

Any idea of a time frame for the manufacture of this firearm?