How to transform an imported 3D scan into a Rhino Object?

Please forgive me if I’am wrong but It depends of the accuracy. I often use a STL scan and translate it to a object. I project lines to the scan and then loft the curves. The only problem I find is to put the curve seams all in one straight line.
see my posting Adjusting many curve seams by moving pointmarkers in Rhino4

Meshes are made from flat facets, so when you project curves on to them, you get a messy curve with all the flat facets. Generally, you’ll want to clean up and smooth out the faceted curves before trying to make surfaces from them. messy curves make messy surfaces.