You have a very nice Jacob Kuntz "wender" or swivel barrel rifle. Great original condition, and interesting because it appears to be original percussion with a full patchbox. Jacob Kuntz (1780-1876) is known for his fine engraving, and overall artistic style of building guns. He worked in Philadelphia for about the years 1810 or 1811, to 1875, and was one of Philadephia's most prominent gunmakers, known for his high quality. The modified back action lock plate style and oval cheekpiece might indicate a mid-to-late 1830s date for this rifle, possibly a few years later. It's a very nice gun, in appealing condion to collectors since it hasn't been worked on or restored in recent history. I really enjoy the extensive engraving on this gun, on the patchbox, cheekpiece inlay, lock plates, hammer, breech block, below the nipple and "snail," and all in Kuntz' style. I also noticed both barrels have adjustable rear sights, another feature not always present on this type rifle. It's a fine piece, worthy of being well cared for. It looks like it might have had a sling on it at one time, based on the mark on the rib between the barrels 4 or 5 inches behind the muzzle. Any chance you can add a picture of the toe, the flat lower edge on the bottom of the butt, to see if it has a fancy toe plate, and if it ever had a sling attachment? Shelby Gallien