alright, its a mod actually. A frankenmouse mod. I took the internals of a WMO and placed them into a more comfortable mouse such as the Microsoft IntelliMouse w/IntelliEye 1.0. (the intellimouse sensor is horrendous, it cannot track at all)
I cut out the bottom section and replaced it with the WMO sensor w/ plastic mount.
All in all, the intellimouse has a much better shape for the right hand than that of the WMO. More palm support + good sensor = win!