How to Build a lofted body from elliptical sections

H forum,

I want to build a body made of elliptical sections ( different ) allong a longitudinal axis,

I tried to define 4 splines uniting points in each of the sections, so as to define faces, and then shells, and then defining curved faces along the longitudinal axis of my "body", and then shells, so as to be able to build a "generic" curved hexahedron, and then fusing all of them along the length, It failed... did not manage to create such hexahedron...

Do you know a smarter approach than the one I am trying...?

It must be a 3d body, not a set of shells...   how must I define it...?

Best regards


Alex