I used a hammer and screwdriver to remove the majority of the rust from the isolators, then soaked them for 24 hours in dilute Muriatic acid. After removal from the acid, I scraped some more. Finally a good detergent wash and the isolators look new except around the edges where they were exposed to sun and ozone.
The clamps had not lost nearly as much metal as appeared to be stuck on the isolators (about 1/8th inch). After a run through the sandblaster, they cleaned up nicely with primer and paint.
I'll be using new "U" bolts as the originals had thread damage due to rust, and I'm looking for poly spring bushings and spring isolators. Of course there are no direct listings for the Mustang II, so I'll have to compare measurements. Its likely that some other '70's car used similar parts.
More cleaning and painting pics later...