If the '46 2 ton is the same as my '50 2 ton COE, there indeed are "bolts" on the backing plate. You adjust the two 5/8" hex heads that are slotted. The procedure is in the manual. On the inside of the backing plate the "bolt" is peened to a 1 1/2 inch disc that has eight "nubbins" that protrude out, acting as gear teeth, which engage the notched end caps of the wheel cylinder. Much nicer than sticking a screw driver through a notch. There is a spring between the backing plate and the disc to hold it in place.
I have a couple of repair kits (not for sale, I might need them) for these and I have seen one other set for sale on Ebay some time ago. The kit has group number 4.678 and part number 3705288. Again, I am assuming it would be the same for your '46.
Kent
