This conversion seems to represent various 3D conversions between .3dm files (3D Nurbs, QuickDraw 3D etc). and SketchUp graphics.
As far as we know, some dedicated 3D model converters should be able to perform 3dm to skp conversion. Unfortunately, we couldn't find any specific about this particular 3dm to skp conversion. If you know something useful, please let's us know in the discussion below.