I am starting to restore the front backing plates on my early 1929 model A. I found there are at least three styles of plates as I have 3 that have different types of adjustment wedge housings riveted to the backing plates. The three stamped backing plates look the same to me, the only difference I can see is the wedge housing. I would like to use the correct style for my 1929 A. I have checked the judging guidelines and couldn't find anything about the different wedge housing styles. Maybe the different styles were just different suppliers to Ford, but I have no idea if that is why there are at least 3 styles or if the different styles are used for different years of production. I have posted pictures of the three types below. Can anyone tell me what the different plates are used for? Thanks for any help.