Mushy brakes 4 life...

I found another Raybestos reference that shows 4.47” flange depth to inward face depth... which is pretty much what I have. It’s now seeming like I have a weird backing plate. I’m not opposed to grinding back the backing plate but I’d like to find the answer. I guess in the past I’ve been lucky to find complete donors and I knew exactly what I had and it was already working.