The closest SN I have listed to yours is 61486 which shipped in 9/1905. I also list at least a half-dozen others in the same SN neighborhood, all of which shipped in 1905. But I also show several with lower SNs which shipped in 1906. That is not unusual as S&W did not ship in SN order. It would be the "Model of 1905" as it has a square butt. As others have stated it has been refinished and shows the usual evidence of a non-factory re-blue. Nonetheless, any Target Model K-frame is unusual and desirable as they constituted only a small percentage of S&W's production.