Ok Allen, I finally had time to put this together. This is actually drawn in 3D.
While I can create a surface on this, it isn't right. It overhangs the boundaries. Let me know if you can figure it out!
BTW, I learned a good bit while working on this, and was actually able to get some of it to work. This is the next to the last part, but the real hard part is yet to come.
Thanks,
Don