Originally Posted by
FBinNY
Or if you look at the option for using a long bolt and nut, I suggested using a drilled out recessed nut as an adapter for the rear hole.
I've done exactly that to allow the use of nutted brakes on a newer recessed mount frame and fork. Get short recessed nuts and drill out the threads with a 15/64" (6 mm) drill bit. It then acts as an exact bushing for the recessed opening and firmly locates the brake bolt.