My first question is, Is there a way to determine a ship's hull form (cross section) from a SB profile?
Unfortunately no, unless that information is provided in the drawing in some way (shading or, most helpfully, a side profile). If you're doing a real ship you're going to have to consult photos. If you're doing an AU ship, I'd suggest consulting the original drawer.
A good resource for plastic modeling, actually, would be Aircraft Resource Center (
www.aircraftresourcecenter.com). Despite its name they do a lot of ships too, and given your background I think you'd fit in. I'm registered there as Just Call me Ray, incidentally