Import 3D Wireframe .dwg File of Machine Assembly with Parts on Different Layers

I have a .dwg file supplied by customer of a machine they want me to make some modifications to.  Thie file was created by a now defunct machine builder so it is all I have to work with.  The .dwg file contains an entire machine assembly in 3D wire frame with each individual part or small sub-assembly on different layers, about 400 of them.  There are many, many thousands of entities in the file, and  I can open it up in Draftsight or Autocad and view the individual parts by turning the other layers off.  I'd like to import this wirframe into a Solidworks part or assembly as with seperate 3D sketchs for each layer so I can easily hide them individually while I construct some solid models of the relevant machine parts for modification.

Does anyone know of a simple way to do this without importing the data one layer at a time and creating seperate part files and re assembling?  It appears there is some layer functionality for 2D wireframe geometry, but not for 3D.  Importing the all of the wireframe to one part file becomes unuseable as I cannot easily hide the numerous imported curves.  In fact. Solidworks suprisingly has a very difficult time even processing the selection of more than a few thousand imported curves at a time from the tree.

I tried exporting to .iges and importing freepoints and curves as 3D sketches, but it requires me to hit OK for each part and it breaks up every feature and bolt hole as an individual part file.  My click finger would be worn to the bone and how would I ever get them assembled together.

SolidworksImport export