Rich,
I would have thought two measurements would have told you the amount of engagement?
Since you are only "worried" about the alignment to allow easier cocking of the toggle; why not a piece of deldrin or nylon cut to size and placed in front of the lug? or just a metal shim cut the size of the opening? Would not have to be attached to anything, would it?
Just thinking in writing.
I know this is not an "elegant" solution, but how much are you going to fire that piece ?