Thanks Michael for your response.

I can see that it's going to take a mental shift, so that I can work with NURBS.
I did look at the links you sent about the Network Tool and see why I can't use it for this shape.

What I did do was to break up the surface up into 8 smaller patches.
I selected the curves of the top 6 patches and did a Sweep between them.
I used the Network Tool on the bottom two patches.

This worked out just fine, but now I have these hard edges between the patches, even after running the Join command.




I've look through the forums for a solution without luck.
Blending the edges didn't work. Trying a Boolean didn't work wither.

What am I doing wrong?

Scott