Antique Hopkins & Allen Revolver

To whom it may concern, I am writing to ask you about a 5 shot revolver that was found about 25 years ago by my father. The only words that I can find on the gun are "Hopkins & Allen M'F'G Co., Pat March 28, 1871, XL. Bulldog 38 Cal. Centre Fire." On the hammer are the words "Pat'd Jan. 27. 85" When the pin is removed the number 2015 can be seen on the barrel. The gun is silver with scrolled etching on the entire piece. The grip is black with a fine diamond knurl pattern. Below the grip is a metal ring. I am trying to find out any information I can about this gun. Thank you for any help you can give me. Sincerely,Cory Barnettcgbarnett@penn.com