I bought a Catalina 25 with a cast iron fin keel in 1981. If I remember correctly, the fin keels on Catalina 25s were cast iron until about 83 or 84, when they started installing lead keels. To the best of my knowledge, rusting keel bolts was only a significant concern on boats kept in salt water. I never heard of it happening in a fresh water boat.
Catalina Direct supplies parts for used Catalina 25s, and they have a keel bolt replacement kit. I've never installed one, but I've heard they can be installed without removing the keel. I've also heard that it takes a serious drill and bit to drill deep holes into the cast iron keel.
Log onto the website for the Catalina 25 national association (catalina-capri-25s.org/forum), and you'll find plenty of information on the matter, as well as people who have done the repair.
Last edited by Sailormon6; 08-31-2006 at 10:04 AM.