I wouldn't strip the plane down just to paint it, if it doesn't need a complete
over-haul. Just sand it lightly with some fine paper until it "all scratched-up",
then do any filling as necessary. I wouldn't use Bondo, because it is too heavy
and too hard to sand. Use a regular light weight balsa filler.

Wipe the plane with some lacquer thinner, and prime it. Get plenty of primer on it,
a couple coats. Then lightly sand the primer to get it smooth, and paint away.

If you get the paint on smooth, you shouldn't need to sand or buff the paint.
Use several light coats. Try not to use more paint than necessary, it will just
keep adding weight.

FBD.