You might check out Mesh2Surface, a Rhino plugin for reverse engineering. Its in active development. I don’t use it myself but I have checked on its capabilities over the years.
Section worked nicely, and I will also try ExtractMeshPart .
Thanks!
no its part of a plugin called RhinoReverse, currently only available for Rhino6, due to lack of demand we never made it to Rhino7/Rhino8. It has some cool Nurbs features not available in Vanilla Rhino.