Post with latest fw would be 2.0 (make sure you have latest JF or it will not report as 2.0). So if you want to go back to stock you need to find the stock FW package usually included. Your drive key shows all f's because you need to load your current 1.9 in the upper slot in JF, then load your target either stock fw or latest ix LT2.0. Then hit the large "Spoof" bar in between them. You will see your key transfer to the target file in bottom slot.