Liberty Rear Disk Brakes for A-Body

That is probably correct, or at least the configuration is the same. The basic components are identical to an Escape rear disk brake system. Calipers, rotors, and other parts interchange per multiple parts sites like Rock Auto. So this means that service parts are going to be available for some time which is a very good thing, and they are cheap and reliable.
I am looking into the Lokar rear brake cable system to make the parking brake functional. Lokar has the correct cable and cable ends to directly use the lever activating the rear brake shoes, something that MA had to cobble together cutting up the stock brake cable. When I get to that point, I will post what I learn trying this approach.