hi friend, i downloaded your model and i search some websites.After analysis i found the solution for you.
1)The fastest and easiest way to open your CATPART file is to double-click it. This allows the intelligence of Windows to decide the correct software application to open your CATPART file.
2)In the case that your CATPART file doesn't open, it is highly likely that you do not have the correct software application installed on your PC to view or edit CATPART file extensions.
3)If your PC opens the CATPART file, but it's the wrong application, you'll need to change your Windows registry file association settings. In other words, Windows is associating CATPART file extensions with the wrong software program.
This CATPART file can be open by using Fileviewpro.
so, you download & install FileViewPro and purchase or crack the license key for good result (to open your model properly)