If you create an account at
www.3dcontentcentral.com, you can upload a 2008 SolidWorks model file and then eveyone would be able to download it as a 2007 model file or 2008 model file format. Use the "FIRST Robotics" category.
If you want to use the STEP files in SolidWorks, select STEP for Filetype on Open.
Use Tools, Mass Properties. Check the Assign Mass Properties box to enter the total mass of your assembly.
Marie