Having scarphed together 4mm marine grade plywood to build Tornado hulls, it is not the easiest task to accomplish. With that said, tortured plywood construction is not a bad way to go. When then bending the hulls into a deck jig, you can obtain the desired shape. Last time that I looked at my Tornados, they did not seem to look like chine hulls at all. So you could in fact look at the basic Tornado hull shapes from the Gougeon plans and scale those down. I know that the thought is to have a beginner boat here, but that does not mean that is has to be one that does not perform. Keep the rigging simple, but allow the hulls to have performance characteristics.