Cleaned up the mounting bracket and lock retainer, then shot with primer. Clecoed the mounting bracket to the F866A1 bulkhead. Used the pneumatic squeezer to set eight AN426AD4 rivets. Sure felt good to smash a few rivets. Bolted the valve body and lock retainer to the mounting bracket. Tested the brake valve and the larger mounting plate reinforces the bulkhead so that it does not flex. Looks like this will suit my needs--finished with mounting the parking brake! Well, almost. I need to order a couple of longer bolts to secure valve etc to the bracket.