Murray,
Welcome to the forum. Very interesting story, yours is to me, because I bought my '55 in '73 as well. Accident in '79 made it sit out until 2003, when a 3-year rebuild began. I suppose the oil pump housing and, maybe, some of the inner and/or outer timing cover, has corroded away. Not that difficult to get water in there when it sits for years. If the water was salty (what, in Florida?), the corrosion would really accelerate. The general opinion here is that the oil pumps are made of lousy metal. My original seems to be working fine, but if the money is there, an SRM Engineering high-delivery aluminum-billet-made pump is the hot ticket.
Do you think you can post some photos here, like of the whole project and of the oil pump? I've now forgotten the number of posts you need to have before you can put up photos.
Anyway, let us know how it goes. By the way, I'm in the Chicago area.
Richard L.