Is anyone familiar with the smoothbore black powder shotgun I inherited (photos attached). It was manufactured in Birmingham England probably between 1832 - 1840. It has Rich Hollis & Sons engravings on lock plate with no model #. Bore ID is approximately 0.678 to 0.688", and bore wall thickness approximately 0.074". I originally thought it was a 16-gauge shotgun, but based on bore diameter it may be a non-standard 15 or 14 gauge. Overall length is 48" and barrel length is 32.5" (includes a 12" octagon barrel at breech section). I'd like to hear on historical facts about this gun, and, if anyone has actually shot with one I'd like to know what black powder grade is used, black powder load, shot size/type and shot oz weight. Also any advise on how to to properly load it with wads & cards. The percussion nipple looks like a #11, but definitely an unknown non-standard type (I guess English type design with too much taper at the cone). Cone tapers down to a length of about 0.335" with a final cone diameter of about 0.218". The cone top is approximately 0.165" diameter with a hole measuring 0.079". The thread journal length is about 0.203" and thread diameter about 0.235", with about 26 threads per inch (it actually seems like a metric type of 6mm-1 thread, so I am not sure if this is usual for an English made gun). In fact, I am not sure the nipple is an original. So, any and all feedback would be appreciated.