I used a plan i bought from stewmac, and used that as a reference to create my nurbs, paying close attention to curvuture. The top and bottom are 4 surfaces in total, because the cross sections need to be specific through out. So both the top and bottom have a top surface and a bottom surface. Simply thickening will not work in this case. I hope i am making sense.
I then used bounding surfaces, planar surfaces, and fill surfaces to drape surfaces over the above mentioned geometry. Used proper relations throughout.
Then, i used a ruled surface around the perimeters, stitched the whole thing together, and formed the solid...