Picked up a used Fender MIM bass for very little $$, it has a known truss rod issue. Seller stated that when he tried to tighten the rod, it would only go so far and then the allen wrench would do something funny. I'm guessing the truss rod nut is cracked (in three places?) which would account for this. Problem is, I can't loosen the nut enough to remove it. I'm guessing the nut is cracked-expanded and this is why it won't back out. Comments? Any suggestions on removing it? If I can get it out, whats the chance can I find a new nut that would fit on a MIM Fender a few years old?