I think moly lube came out later, for use on higher hp outboards, because of it’s WEAR resistance, not so much it’s corrosion resistance. Later, it was decided to call for it across the board. Frank is, as always, right….any good water resistant grease should be fine. If you just have to have moly lube and know a Yamaha outboard guy, ask him for some WR #2. I am no chemist but it sure looks exactly like the old moly lube, to me; and it is used on Yamahas for the same purpose….
Long live American manufacturing!