This is how things line up with the 1/32" offset from centerline. (Blue is the AN3 bolt. Magenta is the nutplate).

So...Here is the revised isometric view showing the corrected 1/32" dimension.

Once I had my dimensions all worked out, I marked all the z-brackets out. Then, very carefully i used a center punch and marked the first hole location.
Once all the brackets where marked I set up the drill press and a drill jig, and drilled the first holes with a #50 bit. Then I opened them up to #40. After that...#12.
I bolted the brackets to the spar using AN3-4A bolts, washers and nuts. I snugged them up and then squared each one up to the spar. Using a thin sharpie I marked the edge on the spar as a reference.
All done. Ready to match drill more holes.