Merge Nurbs Faces - Tween two Curves on 1 Surface

Hi Community,

I’m browsing through the forum, could find some post about merging surfaces but not to 1 single surface.

I’ve modeled a polygon-object/surface in Maya and exported it as Nurbs surfaces to Rhino. The idea at the end is to use the “Tween two Curves on 1 Surface”(Pufferfish) but it requieres only one Surface. Is it possible to merge all Nurbs Surfaces together as one, so i can use the Tween?

I’ve tried to MergeSrf (2 Surfaces each time) but as you can see on the right side, Im ending up on difficult corners, where i can’t merge anymore.

Thanks a lot for your help!

Merge Surfaces.3dm (13.9 MB)
Merge (8.9 KB)