I am trying to create an aerodynamic "ring" that will represent the forward inlet of a jet engine nacelle. The nacelle itself is circular in cross section and proved easy to model. The inlet ring however is deeper at the top than the bottom. I have attached an image showing the thick and thin profiles in their position above the rest of the nacelle. How can I create a ring (or half ring) with the lower (right) profile and the upper (left) profile as shown? I have tried taking a semicircle and changing it to a NURBS curve, to use as a path and using the small profile Extrude Along Path with an increase in scale of 1.5X as it sweeps 180°. The problem is, the base for both profiles are identical in dimension. Scaling it all, widens the extrusion inaccurately.
Have also tried lofting, but no luck there, again using a NURBS semi-circle as a rail.
Have also tried subtracting cylinders then loping a wedge out of the top to provide a tapered ring, which when filleted, does not come close to the profiles required.
Any ideas?