Wow, I haven't checked this post in a few days it, I didn't realize this would get this much attention.

I'm in no hurry to make this, so I'd be interested to see what you come up with. I may have come across a set of the mattracks off of the radio shack hummer(a guy I work with taped a pic up on the wall of his H2 and his girlfriends H3 and what looks like a radioshack hummer. I'm pretty sure he bought it just for display purposes, so I'm hoping to pick up the mattracks). If I can pick them up for cheap I may tinker with them first. I'm having trouble understanding how the long bar on the mattracks works. Is it just there as a counter weight or to absorb rotational inertia? It doesn't appear to be on some versions of the mattracks. Wish we could come across a blueprint.