I have an older S&W Airweight .38 spl. ctg. . I cannot find a model number anywhere... checked inside the cartridge chamber but nothing there. The barrel is about an inch and a quarter long. It has diamond pattern checkering on the grip, and the bluing has rubbed off on a lot of the metal. The release is rectangular in shape with scored vertical ribs on it. I am trying to determine approximate value. Can anyone help, please?