Trying to help a family member identify and find a value to this gun. I don't know where else to turn. This is marked J. Henry & Sons. It is 39 7/8" long, it has a 15" Octogon barrel leading from stock and a 9 3/4" Round barrel attached to that. That seems unusual to me. The closest thing I can find is a J. Henry & Sons Half Stock Plains Riffle. Any help would be much appreciated. Thank you kindly.