I didn't read through this entire thread, so forgive me if this has already been mentioned. I generally stay out of brake mod discussions. There is an alternative to the ATE rear calipers. Calipers from some Maserati bolt right on, and even use the same pads. This eliminates the adjustment issue. The problem will be the hand brake, I suppose you could use some sort of line lock.
If the ATEs are working properly they are pretty good calipers.
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