Which file should I choose?
Use 1SCC311618F0001.dxf (revision A) to insert the supplied editable drawing into your layout. The ZIP contains the unmodified 1SCC311618F0001.dxf.
Use OS400J13.IGS.igs to place the original solid geometry in your 3D assembly. The ZIP contains the unmodified OS400J13.IGS.igs.
