Shelling in Rhino is unfortunately just not sophisticated enough yet to handle this type of object. One of the main problems are the numerous twisted surface extensions needed to create the inside shell and the difficulty of finding their intersections to trim.
One thing that can actually work better - but not perfectly - is to use OffsetSrf instead of Shell. First, extract the surfaces to remove as you would in Shell, and delete them. Then, call OffsetSrf and set the Corner=Round instead of the default Corner=Sharp; also set Solid=Yes. Instead of extending surfaces straight to meet each other, it makes radius blends between them. Playing with the tolerance setting (making it looser) can also help.
Unless you absolutely need the sharp corners, this usually works much better - but still often leaves a few open spots. These can usually be patched, with more or less work depending on the configuration. For example, I removed the lower surface from your object (after fixing the object so that it was closed and converting the file to meters as @JimCarruthers suggests), then I ran OffsetSrf with 0.5 meters to the inside, Corner=Round and Solid=Yes. This gave a result with a couple of naked edges in one area, which I was able to fix by just removing one surface and replacing it with a Patch. (it’s outlined with a red curve.). Makes a closed, solid polysurface suitable for 3D printing (but obviously not at 1:1 ) FWIW.
Closed-Meters.3dm (1.3 MB)