The keel on my just-purchased 1991 Hunter 18.5 is rusty. The odd part is that the top 3 or 4 inches where it is attached to the hull isn't rusty. That part has the same color as the bottom anti-fouling paint. Was the keel originally coated or painted completely? And speaking of the bottom paint, I've heard that some paints can be "touched up" rather than a complete re-paint. Is this true? And if so, how can you tell which ones can be re-touched? Thanks!