[aerohead]

With woodworking skills you'll be able to pull off pretty much whatever you set your mind to.
I'm in the midst of a cedar-strip (canoe) aeroshell for the Dodge pickup.
The 1941 de Havilland DH.98 Mosquito fuselage was formed by glued plywood laminations compressed into a concrete mold under pressure from an air-inflated rubber bladder.
If you get desparate,galvanized expanded metal lath can be plastered with drywall compound (USG,Sheetrock,MURCO,etc.) to create a fast-build male plug from which to do a plastic-faced plaster splash in which to wet layup a final compound curvature part.
Some of the low-buck lowriders I grew up with were forced to do such things to create their one-off custom rides.
Plastic body putty on lath has also been used to effect.