Mercury Kiekaefer 798 898 AX2765 rotor Mark 40 KF9 KG9 FM magneto ignition . NOS rotor in original Fairbanks-Morse box.  Has part # 397-798 and AX2765.  Little research shows it fits early Mark 40 models KF9 and KG9. Comes as pictured.  Be sure to check fitment before buying,  feel free to ask any questions.   I have a fair amount of other NOS parts I will be listing in the next couple weeks.  If youre looking for something and don't see it in other listings, send me a message.