That gun has been rebarreled with a 44-40 bbl, the FSS marking is the later stamping, not etched. However it could be the original bbl, as I believe the serial numbers have been restamped, and the letter may not even be for that particular gun! The engraving looks like an amateur was practicing on it! The only thing I like about that gun is the beautiful grips. It would make a "blingy" shooter, if you can get it cheap enough!