About this 3D model

Osprinting filastruder official case files did not work for me. The DXF files seem to be not correctly formatted. So I opened the step (.stp) files in inventor autodesk student edition (I'm a student) and exported the face of each file into 2007 DXF format. 2007 DXF has been the most compatible for me. I think the format is defaulting to " units, and you can use either "autodetect" or "inch" when importing to another program.