I have a pre-70 Sunfish that I bought in the fall and am preparing to take out this summer. It has the old style rudder and all the associated hardware, but it was all detached from the boat when I bought her. I've cleaned it all up and am ready to attach it, but I am curious as to how the bottom plate attaches through the top plate and flexible plate. It seems there is a long brass bolt that I'm missing that pulls these three pieces together. Wouldn't a movable bolt all the way through the hull leak, though? And, if it's not movable, how can the plates move in relation to each other?