I've read one of your post where you say you are tighting your keel's bolts every time you pull your C&C 34 out of the water...
May I ask what torque you're using ?
I recently purchased a C&C 30 MK1 (1977) and there is a very little line in between the hull and the keel ... and I fear that I may need to do something to insure the safety of that boat before putting it into water. It is going in the water on Thursday and will stay in the water until October.
I will speak to the old owner and ask him if he has done anything with the keel since he had it ( he owned it for 27 years ).