undulating surface using image sampler

Hi guys!

     I am trying to create an undulating surface using an image sampler.  I was able to create the surface, but have know ran into a snag.  I am trying to merge all the faces to create one undulating surface to bring into Revit.  My current script has me creating different surfaces that move back and forth.  I have attached the script, and file.  Thanks for the help.  I am using rhino 5.