The transmission takes ATF- I use the Dexron III from NAPA, but everybody's got their own preference.
You'll find that fiberglass resin doesn't stick to ABS for very long. Most of us will use plastic welding of some kind or make up some paste with shredded ABS plastic and acetone. You can use fiberglass fabric along with the plastic/acetone goop to make the mend stronger.
Depending on what the .22 was, it looks like you made a pretty good deal.
Good luck!
Stuck in the seventies- not in the swamp.
(6) Attex, a Hustler, a Super Swamp Fox, (2) Tricarts, (3) Tri-sports, a Sno-co trike, 3 Dunecycles, and a Starcraft! ...so far