Welcome to the forums from the Wiregrass! You have a .32 Regulation Police revolver from 1922/23. It appears to be original finish...the hammer and trigger are case colored, not blued. The RP was made in .32 Long and .38 S&W calibers, but the .32 Long was numbered with the .32 Hand Ejectors while the .38 had its own serial number range. These guns had a rebated (stepped) backstrap to accommodate the extended and patented square butt grips. The patent date for the grips is in your last picture. These little guns are fun to shoot. For comparison, here's a picture of mine which HAS been refinished and the hammer/trigger blued. This gun has a 384xxx serial from mid 1924.