How to Make a convoluted pipe

Attached is a polysurface I made several years ago. I have always hated it. (1) The surface is too complex for what it does and (2) [big reason] the pipe surface really should flow smoothly. Ideally, it would be a single surface that bends back on itself.

The process is complicated by having a straight line edge but I was wondering of anyone had any suggestion on how to approach creating such a surface.

Problem Chock.3dm (3.7 MB)

I have played around with this. Using Sweep2 I can get this. The problems here are that (1) I need the bottom to go into a curve (infinite radius at the top) rather than being flat all the way through; (2) the throat should be wider; and (3) the bend back area should be rounder.

That seems to call for more curves which seems to mean networksrf. That networksrf does not work well with this shape.

Still looking for suggestions.