A woodie body is quite a complicated thing. However on my 36 woodie most wood is flat and straight except for the roof frame. On the later woodies like 42-51 there aren't many pieces that are straight. If you have made wood for boats making a body shouldn't be a problem for you. The woodie makers out there now are making the whole thing including fiberglass firewalls. It would be helpful for you to have access to a 46-48 woodie to get an idea of how to shape the pieces. I think a 4 door sedan would be a better starting point than a truck.
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