The hole in the bracket is sized for use with a 10x32 socket cap screw and has a 5mm through hole with a 9mm wide counterbore (I did this to sorta copy whats seen on the ROTJ Hero since we’ve no good photos of this area on the ESB Hero). The bracket itself is 17mm wide. And I sized the mating inside holes on the clips to fit a 5/16th x 1/2” long threaded aluminum spacer (these are readily available at any local ACE hardware store)
All the other holes are sized for a M5 cut tap so set-screws can be added