Save Assembly As Part Has Missing Geometry

Hi All,

I have a .stp file that I'm trying to turn into a .sldprt file. It opens as an assembly so I have to save-as a part. Not a big deal. I've done it many times before. This one just doesn't want to do it. I've tried all three save-as part options (Exterior Faces, Exterior Components, All components). I've tried dissolving all the sub-assemblies. That was even worse. I've even asked every SW person I know in two companies, but nada. So if anyone can offer some aid I would greatly appreciate it. The .stp is below if you want to fiddle with it.

Thanks

SolidworksAssemblies