[Woodchuck]

The problem is this is faulty info, here is my housing measurement from my Versailles rear end:

Add 5" for the common 2.5" axle offset and 1/4" each side for disc brakes and what you have is 57.75".

Those are axle flange to axle flange measurements, not housing flange to housing flange and are, as shown, pretty much correct.

The parking brake "issue" is one of leverage as the levers on the caliper are way too short to work with a hand-operated control, being a foot pedal originally. I'd like to see an experiment with drilling a new hole in the brake arm that attaches to the transmission crossmember, closer to the pivot, which would increase the travel of the hand lever but also increase the mechanical advantage.... leverage.