This might be good for some of you 3D folks. I found it surfing around today.
Tank History 1.0
The collection contains 155 models of tanks and self-propelled mountings based on serial tanks. Many tanks commercially produced during 1917-2000 years and the most interesting prototypes are included in the collection. Technique of more than 20 countries all over the world is represented.
found another usseful link w 3d models