Hi Zoxesyr.

 I found a page on the Sketchup-warehouse that has Traveller related models, including a nice Free Trader.

http://sketchup.google.com/3dwarehouse/cldetails?mid=3c50b327b256a640dd821470ed8efdff&ct=mdcc&prevstart=0

They are in SketchUp format so you'll need the SketchUp program. The free version doesnt export to .3ds or .obj but there is an online translation service  - https://www.babel3d.com/  that may be useful - they have a 7 day free trial. I havnt used them so dont know how good they might be. 

There is also this blog - http://traveller.chromeblack.com/ that features some fantastic 3d models and articles centered around the Traveller universe. Maybe you can contact the author and see if a deal can be made. Good links at the top and side of the page.

If I can ask - is this a personal project?  I used to play Traveller years ago and although I've been out of the scene for a while I'd love to see what you're producing.

MAF