I have a shotgun given to me by my grandfather. My great grandfather bought it sometime in the early 1900s. It is marked as follows:
Right barrel marked "Eclipse Commet"
Left barrel marked "Choked"
Rib between the barrels marked "No. 51xx TWIST FINISH BELGIUM"
Right lock is marked "Eclipse Gun Co"
Left Lock is marked "Eclipse Gun 02"
It is a double barrel 12 gauge with external hammers.
It looks like it has Damascus (sp?) barrels
I can get pics if anyone wants, but it looks like a basic double barrel 12 gauge with external hammers.
The only advice I can give is don't shoot it if it has demascus barrels or you will be hurting afterward.
No worries, I have no plans for shooting it. The sears and sear engagement on the hammers are totally shot. My grandpa said the last time he shot it, both barrels would ALWAYS go off. He also said he had to use light loads, because heavy loads made the action open when it was fired. Both barrels are heavily pitted near the chamber area. I'm assuming this is from shooting black powder loads, and not cleaning afterwords. I think it's a neat family heirloom though. All the times I tried to search something online, nothing has come up. It's probably just a run of the mill shotgun from the turn of the century.
Eta: The twist pattern does seem to be visible on both the outside of the barrels and in the bore.