Randy,
Your hammer gun is pictured in my circa 1900 Midland catalogue.Midland called this Gun their; "Rabbit"Gun the price was 1 pound 19 Shillings. They describe it As;"The best gun ever offered by any one for 39 shillings!" Even for 1900 this was a remarkable price!" Their best hammer gun in this catalogue sold for 12 pounds,6x the cost of yours.
As stated by others your gun was made between,1888 & 1904.The proof marks are Birmingham black powder for a 12 G gun bored at 13G at the time of proof. The chambers were in all probability 2 1/2 at time of proof. The pictures; posted of the barrels suggest that they are Damascus that may have been reblued.
For your safety;
Check the barrel dimensions prior to use[Bore Diameter,Chamber length and wall thickness]In my experience many of these old low cost gun have had their barrels butchered or shot out by previous owners. .
Last edited by Roy Hebbes; 01/01/14 03:51 PM.