Get it running and worry about the free wheeling latter on.
The brake works on the gearbox layshaft, not the wheels nor axle .
It locks the diff so one wheel turns backwards and the other turns forwards.
This is by the way the same way the P position on an auto gearbox works.
Thus if one wheel can slide, the other will rotate.
The parking brake in under the turret and is a SOB to remove.
It is a flanged switch with a pair of barbs that stop it falling out and you really need to be triple jointed to get it out in one piece.
AFAIK it is just about unique to Cub & Bolens ( pre MTD )
You will not be able to pull the wires off with it in place and to get it out you really have to remove the rear body panel which is 2 man job because it is a big lump of metal & awkward to handle.
Good news is it is only held in by 6 bolts , 4 in the foot boards under the rubber mat and 1 each side of the seat which comes off if you are doing it by yourself or can stay on if there are two of you .
One bolt for each for brake & forward pedals, reverse stays where it is.
The wiring to the seat switch is well protected but the wiring to the brake switch in not,
Follow the thick wiring loom down from the top of the turret & you will see 2 sets of wires branching off at the bottom & going back into the bottom of the turret.
These are the reverse lock out ( green & white ) & brake ( yellow ) switch wires