just check out that multi power shift.
it was a great option in its day, but its day is long ago. basely a type of automatic shift, like case-o-matic.
my local dealer said when he traded for a tractor with multi power, he traded for it assuming he would have to have the multi power unit rebuilt, before he would put it out on the lot.
the last model 165 mf made had the 4 speed trans with h/l, no multi power, that would be the one to get, but I guess they are hard to find.
however, others have had the multi power tractors for years, with no problems.
some would not let kids drive them, if the multi power goes out, then your only braking is with the wheel brakes as you will have no engine braking. So be sure the wheel brakes are in excellent condition.