In the process of reassembling my '53 Manhattan, I dug out an NOS front brake backing plate that I got from a former dealership in the year 3. It is identical in every respect to those I have seen before except for the brake adjusting cams. Instead of a bolt with a tab on top coming out of the nut, these appear to be a 3/8" square drive atop two thick washers, one of which is split. The cam side is the same as the standard type. Have never seen such-must be a later replacement, as I've had '54s that were like my 53. First thought would be that one simply adjusts by turning the square head, but at reasonable force levels it doesn't move. Before applying sterner force I thought I'd check to see if anyone is familiar with this design.