Greylock

i have a 750 ss xi my problem is i snapped off the aluminum piece that the large nut that holds the cable in place and seals it to the hull ! i have looked at all the parts diagrams online and my dealer couldn't figure it out either.
there are two small bolts that i also removed but it wont move and i cant see any access from inside the hull.Does anybody have any experience with this problem? looks like it not serviceable thought someone might make something aftermarket to fix this problem.