I've had a 1860 Spencer Saddle Ring Carbine (plz forgive me if my nomenclature is wrong) in my possession for 33 years. Prior to that it was always at my Grandparents house. I am about to gift it to my brother, but would like to know more about its providence if able. The serial number is #50073. Can anyone give me more specifics like when it was made or unit of issue perhaps? I was too young at the time to ask how the family came into possession of it, so now it is just an old gun, but in good condition, with no known history. Thanks in advance.