Pull the drums off your spindles. Grab some aftermarket rotors for an early 2000s Mercedes E-class. Try a diesel or smaller gas car. They should have 11-1/2" rotors 1-1/4" thick.
Open the center register of the Mercedes rotor and it should slip over the drum brake hub.
Build a bracket to mount a common single piston caliper and you're good to go.

I used 2005 S55 rotors to get a deeper offset. I had to pull the rotor back as far as possible to clear the pistons on the outside of the caliper.


Check with your local MB dealership. They might have a used rotor or two for you to test.