I inherited a Rolling Block from my grandfather. The thing is completely devoid of details. It has a bayonet lug on the right side of the barrel at the 3 o'clock position. There is no serial number, proof marks, or caliber indication. The bayonet lug and lack of serial numbers have me scratching my head. If it was military why the lack of serial numbers? If civilian, why the bayonet lug? Any help would be appreciated.