<http://blog.modernmechanix.com/2006/11/17/motor-scooter-burns-lpg/> ....Belt drive? <http://blog.modernmechanix.com/2006/11/27/belt-drive-replaces-wheels-on-novel-motorcycle/>
"Fitted with a machine gun, the cycle could be used by dispatch riders" Too late, too late. Mind you, I doubt that thing could have got out of a hole or up a hillside that any normally knobbly-tyred off-roader couldn't have, so no progress with that invention.