that's a cool trick burrman. i learned something new today. i used what you showed to at least get the needed curves. rhino being what it is, it screws up the blend quality. but i was able to extract the curves, delete the blend and use either 2 rail sweep or network. both produced good results.

just a note. some of the intial curves don't line up and are not in a plane. i was just trying to work with the original geometry. i had to do a lot of tricks just to get the 3d curves shown. to do this better i would make all new curves that line up properly. then use what burrman showed.