Hi Don,
Yeah I hear you now. Using cross section can give you exact control of the surface your going for. Trying to draw those cross sections is your challenge. In the file I posted last, you can delete the surface and view the curves. They were just created from a surface generated in the manner you posted before so the results are the same.

Bobcad is limited in its surface creation tools and if you need a more powerful toolset for this you may need to look for other packages that are more specific to this task to acheive this. Higher end packages can give more control over where your surface goes and how the edges blend through.

I see the result your after but might be beyond me with the curves supplied.

Maybe Allen has a good way to proceed.

Bueller.....Bueller?