OK, just had another thought here after thinking about it for awhile. I'm a good Engineer, and good Engineers are lazy - we want the easy way out.

Chances are, the back of the cowl is planar. The front of the cowl is too - at least after the rounded edges of the nose. Draw the planar outline of the cowl back edge and draw the planar outline of the cowl nose. For the planar outline of the back edge, imagine that you set the cowl down on a piece of paper (nose up), and trace around the edge - that's your bottom surface. For the nose surface, pick an imaginary cross section slice where the rounded edges from the plane of the nose stop - that's your second surface. I'm assuming you know how to take a mix of lines, arcs, and curves and define them as a contiguous surface (Create Complex Shape).

Use the "Construct Skin Surface" command in the "Create Surfaces" palette to connect the two surfaces. Then build up the nose with some extrusions - revolved and extruded arcs for the rounded edges, and use the "Punch Surface" command in the "Modify Surface" palette to do the intakes. Before you do the intakes, if you need a finite thickness, simply draw a fence around the whole model and do a Scale-Copy with the Active Scale set at a percentage to create the thickness you desire. Do this before punching the hole, and all the extrusions and surfaces for the intakes will be created automatically. If you need it, cap the thickness at the back edge with another complex shape by drawing a surface on the two outlines and declaring the center section a hole. You may need to delete (or move to another level) the original two surfaces of the nose and back to open up the model from the inside.

Does this help?