Don,
The tiller I picked up is a used Japanese one. It is called a 6 foot tiller, but the actual tilling width is 5'6". I don't know if it is a Yanmar or one of the other Japanese manufacturers, but it was originally that greyish-green color that a lot of Yanmar stuff is, and someone used a rattle-can to paint it red. I will probably strip it and repaint it this summer (a nice Kubota orange, of course!).
I got lucky in finding this one - most of the Japanese tillers seem to be in the 4-5' width range. These can be really good deals, but you have to check them out to make sure they aren't wore out (check the gear lash!) or have leaky gearboxes. Even if the tines are pretty wore, they are easy and cheap to replace. I've seen some that were pretty well rusted out too. For $600.00 (as compared to $1500 - $2500 for a new 6' Kubota, Caroni, or First Choice), I think this one was a great deal.
I have been running this one slightly offset to the right, and it only leaves about 4" of the left rear tire track untilled. A full 6' wide tiller would just barely till out the tire tracks. I've tilled a little over an acre with it, with about a third of that new ground that hadn't been broken in 35-40 years and it has performed flawlessly. Some of the ground had rocks bigger than softballs, and it was no problem going over it with one ~4" deep pass and one pass set at maximum depth (about 9-10") - it just ripped those rocks right out of the ground!
-Chuck