I have very carefully gone over the three objects to make sure that the UV maps had no overlapping or 0 area faces in the UV map. In the case of the cowl I actually removed parts of it that were not part of the main exterior surface. These consisted of things like the cylindrical surfaces for the air intake holes, the edge and internal surfaces of the exhaust cutout, the internal air intake passages (behind the holes on the side of the cowl) and the front ring that is next to the spinner which are all now separate objects now. The cowl in now much simpler (still a fairly complex shape in the chin scoop area) with no folded over edges or inside surfaces.
So here are some screen shots:
These are high res screen shots (about 4.5 mega pixels each) so you should be able to see all of the necessary details. The background in the UV map screen shot is the actual texture being used. The line and hole detail in the texture was used to create the normal map.