alot of these were later used as saluting guns. Do your self a favor, don't mess too much with that breech, the BATF&E consider even at its age and with the lack of suitable casings, a "device of mass destruction" as its breech loading. (no regs really for muzzle loading guns, our outfit has one of each, a Civil War prairie howitzer replica, treated like black powder rifles, BUT our WWII 37mm anti-tank gun, WOOF. Took me two years to keep them from making us destroy an historic gun, they want a hole cut in the chamber the size of the muzzle, THEN they'll show you how to weld a shotgun barrel in to salute with. Didn't happen but the hassle. So our 8 inch M-115 will remain demilled. There is a company here in Ohio, Gillmor Ordnance in Old Fort, Ohio that can probably assist you in casting a mount for the gun, he manufactures all sort of cannon, pieces, parts, ships bells and more. Check him out online. He makes cannon from BB shooters to full 9 pound plus ships guns and field pieces. Works in brass, bronze, aluminum and iron. The pics below are of his 'pirate boat' an ex-32 ft Columbia sailboat he mounts six guns on and the other is a prairie howitzer with a custom Naval Sea Cadet insignia cast into it. He does alot of work for the movies, like "Last Samurai", Gods and Generals, Field of Lost Shoes, the mini series Turned, and more. Does good work reasonable too from what we've (Firelands Military Vehicle Group) have bought from him.