Thanks for the pics, they make things easier to follow.
I was concerned that having two open bolt holes in the side of the hull was a recipe for disaster. However, Ray Howkins (Sealia) assures me that you have to stand the boat on it's ear to take on any water. He also suggests a couple of rubber "O" rings on the legs to keep out any seepage when the legs are attached.
So problem of holes is not such a problem except when it rains.
With this in mind I shall purchase a couple of rubber bungs and a more efficient bilge pump!