Oday 30 keel
I own a '78 Oday 30 with the fin keel, I have done a complete rehab of the boat one of the things I had to do was strip the bottom and fix a few blisters during this process I noted some small cracks in the hull around the front and rear sides of the keel they were like gelcoat cracks. I ground them out and found they were in a fill fairing compound that had been used to fair the hull keel joint, the actual keel hull glass joint was sound. It looks like Oday used a separate keel moulding and bonded it to the hull ( no bolts ). To fix the joint was ground out to remove all of the fill and recovered with glass mat and epoxy untill fair (a lot of work and all overhead ). I made this fix 3 years ago and sail the boat about 3 to 4 times a week in the summer in all conditions, I haul out every winter and the keel takes about 30% to 40% of the boats weight no sign of any further problems with this area.
Hope this answers your questions.