How old is a damascus 8 guage black powder center fire shotgun made by davinport firearms serial number 270?

W.H. Davenport Firearm Company made shotguns for the Shapleigh Hardware Co pany of St. Louis, Missouri.The founder William H. Davenport held a great many papents on breech loading firearms. the company devoted its energies almost exclusively to single barrel shotguns of very inexpensive grades, making both house and brand names. an 8 gauge goose gun in excelent condition can be worth $300. and in poor condition $100. They were manufactured between 1891 and 1910.