With that serial number, I suspect you have a .38 Military and Police, Model of 1905, Fourth change, made in the 1920's. S&W didn't assign model numbers until 1957, but that basic gun became the Model 10. The number under the crane is an assembly number to keep the fitted crane and frame together during final finishing and assembly.
Two cautions. That revolver does not have a very reliable hammer block safety, so if you carry it I recommend keeping an empty chamber under the hammer; also avoid use of +P and +P+ ammunition. The former could damage the gun, the latter would probably destroy it.
Jim