The first and second pattern F/S knives had handles made from brass, like this one of mine (2nd pattern). The third pattern had a handle made from cast aluminium alloy (rubbishy aluminium/pot metal). There were a few with wood handles. I'm not sure if the American made versions had brass and aluminium handles or just aluminium?
I'm reluctant to mention this F10 but the one you've pictured looks suspiciously like the ones of recent Indian(?) manufacture that have been offered for sale by a dealer in the U.K.