The old Smith should have the trademark on the sideplate-hard to tell if it's there in the photo. S&W started assigning model numbers in 1957, the serial number from the bottom of the grip frame would be a big help in narrowing down the year though Smith didn't necessarily ship in order of serial number. The revolver shown started as the .38 Military and Police Model of 1902 (prior version 1899-1902 had the round butt frame). There should also be another screw in the front of the trigger guard (those guns whether K or N frames are commonly referred to as 5-screw revolvers). In 1945 the serial number began with the letter "S", in 1948 the serial prefix was changed to "C". The one you posted shouldn't have any letter preceeding the serial number.

I agree with .455 on the value as long as the chambers and bore are in decent shape. Cool old revolver regardless.