These were used after the Phillips head style posts. They were used at the end of the era for FRT1. These are correct for FRT1 all the way through to the early FRt4 era of manufacturing. Remember the FRT3 was manufactured for many years after the FRT4…

LOOK CLOSELY the rim or the edge at the top of the flat head … the “head” part of these posts had a little ridge. That ridge authenticates these as 1980-1982ish. These were machined hard steel and it makes a tone difference. much better steel equals better tone…Also the top of the “flat head” .. the round area is smaller than modern floyd posts and the slots for the flat head screw driver is a little wider.

get these if you want a better set tonally and for 1982 FRT3 and earlier. Hard steel actually makes way better tone.

ALL These Prototype posts are .24mm wide an thats how you know they are prototype floyd rose studs. The modern posts are wider.