You have a ".38 Military and Police Model of 1905-4th Change" The serial numbers for this gun run from 241704 in 1915 up to 1000000 in 1942. As a frame of reference, the one I have is 659XXX which is fairly accurately dated to 1936. I would guess yours is late '20s to early '30s.
Your gun has obviously been re-polished and nickled after it left the factory (the lettering and logo are not sharp. Indicated heavy buffing) and the grips are not factory either. Thus, it has little collector value, not that these guns had much collector value anyway due to the vast quantities produced.
These are still fine revolvers. Most have very slick actions due to the skilled employees who made them. NOTE! DO NOT USE +P AMMO. These old revolvers didn't have the heat treated cylinders of the newer versions. They can be very accurate with regular ammo, especially wadcutters. Enjoy!