I don't mean to be contrary or arguementative. I want good info distributed among the owners.
But the fact is the hull of C30 is over an inch thick of solid glass along the hull bottom and in the bilge areas. The cosmetic "cover" of glass over the wood is 1/4 or less and the amount called for recovering by Catalina is even less. The 4500# keel would never stay attached if there was only 1/4 under the bottom of the wood.
Since we both know the bolts do not stretch, then (IF) your bolts were "sinking", the only result would be that the lead keel was separated from the hull by an equal distance. And the bolt hole(s) had to be open to sea water which of course allowed water into the wood area.
Your keel was severely damaged somehow and the PO or surveyor should have noted this as a condition of sale.
As I said in the first email "Only the worst cases of grounding the keel would result in movement of the bolts causing any leaks.".