Yeah it looks like the center bolt circle is used as a spacer. I may have to cut the spacer/bolt cicle out, or machine an aluminum spacer.
SKY makes that plate if you really wanna buy something.
http://www.sky-manufacturing.com/new/detaproduct.php?id=81I just cut out the center and used it. You'll want to tack weld the brake line mount where it connects to the backing plate so they are in the same relationship when you cut the backing plate apart. This allows you to have a factory mount for the brake line that uses the two caliper bolt mounts. now you can take off the calipers without having to re-bleed the system. Hope that all makes sense.
