Sure, let's keep at it.
I went back and looked at this
THREAD. Did you ever get the frame rail end of the cable(s) secured correctly? What's shown in the photo of your cable isn't right and would likely cause that lever to make contact with the backing plate. Can you show us how the PB cables are mounted at the frame rails?
Attached is a photo of the machined end of one of my old PB cables. Note the notch, that's where the bolt in the frame rail clamp rides and secures the cable so it won't move. I believe that's your problem: your cable end is past the frame rail clamp and that's why the lever hits the backing plate. The frame rail end of your cable doesn't look right to me.
Thanks,
