not an exact match , your pistol doesn't have the birds beak grip . It has the the spur trigger and I agree with the time line Bosnmate mentions a Smith and Wesson version , H & R made a knockoff version that is close to the frame style of your find . Could be S & W but ,, My guess is 1875 Harrington Richardson Defender .
Andi
. I'm located in otsego mi~ (allegan county)