Surface modeling

I have a model with 4 lines that I want to create a surface out of. Three of the four are compound curves and the other is a simple line. I have tried patch, networksrf and edgesrf but I always get a wrinkle at the narrow end of the shape. I rebuilt the curves and I’m still getting a wrinkle.

Any suggestions would be appreciated.

Thank you.

CosmasSurfacing model.3dm (138.5 KB)

There is no single command that will make an accurate surface from those curves. Keep in mind, the topology of a NURBS surface is a rectangle.
Based on your curves, they suggest they could be trim curves that could be used trim a simpler surface. The only curve that could be a surface edge is A. If B and D were extended and rolled under, then the 4th edge could be and extended C curve.

Here are some visually similar curves and surface that might give you an idea.
Then you could use your curves as a trim boundary and get the shape you’re after.

Thank you John. That makes sense.