a friend of mine is rebuilding/restoring a rare 70's Rokon flat track racer. Its got (i think) a 360cc 2 stroke, pull start rotax motor with some crazy snowmobile style clutch setup.
i looked rokon up & they still build bikes. 2 wheel drive bushwackin' bikes.
i like that crazy list on the site you posted, just letting you guys in on another rare breed i stumbled across recently.