Harrington & Richardson single barrel shotgun
First let me begin by saying I know VERY LITTLE about shotguns, never shot one, had no desire. Going thru some stuff of my Fathers found shotgun that I remember him saying it belonged to his Father. This I know Harrington & Richardson single 26" barrel, exposed hammer. no model #, stamped on side Feb.20-27 either 1899 or 1900 hard to tell both could be wrong. Serial # in 2 places 207030 that I've found. Problem is it is in two separate pieces, there is a missing part that holds the barrel into the stock, just guessing but looks like it would be a rod/lever device. Could anyone tell me what I'm looking for ANY help would be greatly appreciated. Thought I would clean-up this old gun, not to shoot and give to my Son, something from his Father,Grandfather, Great Grandfather. Thanks.