Lloyd,
Thank you for sending your DXF files to us. Our team have analysed them and they do indeed have no objects in Model Space, as the error indicated. They do have objects in a Layout Page (Paper Space) and if you have the full version of AutoCAD, you can Right Click on a Layout Page tab and choose "Export Layout to Model". This file can then be successfully imported into Stardraw Design 7. Unfortunately, the AutoDesk TrueView does not support this feature.
I note that your DXF file also came with a PDF file. Did you know that Stardraw Design 7.2 supports Importing of PDF files? Quite often, a manufacturer will be happy to provide PDF drawings of their products rather than AutoCAD DWG or DXF files. Simply choose "Import PDF as New Project" from the File menu in Stardraw Design 7.2
I hope this helps and explains the various methods of importing manufacturer drawings into Stardraw and please do not hesitate to post on this forum if you have any further questions or problems.