Here is the site for Omnitrac. I think GripTrak, the company that made_makes the steel track assemblies for combines has belts now too, and their site is www.griptrac.com
We ran two sets of Griptrac tracks on 2388's last fall. Check out the 2002 season at www.hollandharvesting.com for photos. let me know if you need more info.
Those pics of the mud are awesome, but does bring back somewhat disturbing memories of a rear wheel assist l-3, with a cat D-9 attached to the back to rescue me.....