I've a HUGE admirer of his vehicle, and I'd give someone else's left jelly bean to own one.
Have you considered the wood frame, with thin plywood curved over? Fiberglass it, remove the fiberglass, flip it over, and build up the underside? Who cares what it looks like inside.
To get it smooth as glass like Dick did, you'll need to spend days sanding, filling, sanding, filling... If you're not going for museum-quality finish, I'd say just get 'er done for your first build and refine it on your second. My plan was to build a single-seater for in-town commuting, then on the second build make it tandem and focus on highway MPG.
__________________
|