Try generating your cowling in autocad using "edgesurfing" (autoCAD) (surface modeling YUCK!!!)
Explode your edgesurf & strip off the sections that you wish to use... (this is not quick)
Make sure you have good X,Y,Z reference coordinates for all sections removed from your model, so as to be able to loft the sections into a solid model (they MUST be kept in the correct XYZ in order to develop a good model.

Good luck,
HO-229