Jackson Proflex - putting leather bit back on after changing wires

[katz in boots]

(Jackson proflex boots are discontinued, this may apply only to those who have some experience with these boots)
I took the back off my boots to replace frayed wires, then glued them back on. No problems with all that, however I cannot get them to sit flat enough to the boot.
They impede the action of the boa tightening knob.  I've repeated the process a couple of times, and ended up taking them off altogether in frustration.

Anyone here done their own boa wire replacement & encountered problems, found a way to avoid this problem?