These brackets are worth the wait. A truly excellent product.
VERY Nice bracket Dave. Wish this would have been available a few years back when I had to fab my own.
I built a Factory Five Racing Cobra replica with IRS and went with the 11.65" rear rotor. I would think you may have a potential market with the FFR crowd as our cars tend to need more rear brake bias. The only bracket option I have seen to fit an 11.65" rotor prior to yours is for the Cobra rear calipers - that I believe uses a smaller piston compared to the TBird / MarkVIII / XR7 calipers.
You should consider getting the word out to the FFR builders that this bracket is available to allow a different caliper.