There is something very strange here. The revolver has the pre-1927 extractor rod knob style, therefore there would be no letter prefix to the SN. It also appears to me to have no "Made in USA" frame stamping, but I can't tell that for sure. If so, that would put at no newer than 1922. And the barrel patent date would put it after 1914. It has a square butt, which it should not have with the SN (25xxx) given. Additionally, the grips are of the post-WWII period, and cannot be original. Please post a picture of the butt clearly showing the serial number. Are you sure the SN is not 25xxxx (which would make it from about 1916)? I'd bet it is - it's the only SN that makes sense.