I am considering the purchase of of a 1970 Columbia Mark III. I believe I can get it rater inexspensively becuase it has some problems, the main being that the keel is badly corroded where it meets the hull. It has a lead keel and seems to have a shroud or flange coming up about 8 inches which isnt something I've seen before. This flange is begining to seperate from the hull but the keel it self seems to still be in a normal postion, however the keel bolts need to be replaced. Does anyone have any idea on how this might be fixed or what exactly is going on. I plan on taking this boat around the world, from the east coast heading west. Do you think this would be a suitable boat? Thanks a lot.