10" Backing Plates

I changed to 10" rear drums on my 64 7-1/4 a few years ago. I bought the backing plates from a FABO member, possibly Lee Robinson. I came up with all the other parts. Then I sold the removed complete 9" brakes to another member who needed parts. So nothing left to make a comparison.
From what I remember they are attached with 4 fasteners instead of the more common 5 like on the bigger axles.