That deceptively simple looking lower hull isn't the easiest thing. There are subtle changes in curvatures and angles all over it. I was tossing it around in my head for more than a week before I actually sat down to try to make it. Although it didn't come out exactly the way I hoped I did learn something from the attempt. Hopefully next time I'll get it right.
One thing I learned right off: I find it highly doubtful you could carve the lower hull out of a solid piece of wood simply because of the angle changes along the sides and that the leading edge is curved rather than straight and the craft tapers in towards the front. To do it as a scratchbuild model you'd have to make a framework much like a boat's hull or aircraft fuselage and then put your sheet balsa or sheet plastic on top of that. That's where this 3D model (assuming I can make it) could be helpful because I'd be able to get the exact shapes in cross sections to make the frame members.
Later today I'll try again.