Note the fully enclosed chaincase, which is what Peter Furlong made his name producing, as aftermarket fitments to motorcycles of all kinds. Ironically, MZs were one of the rare marques which fitted fully enclosed chaincases to all their models as standard!
November 2012 update: Currently in bits with owner Andy Tribble after spending several years with John Bruce, who made some modifications for Andy. PNB

Henry Mayhew's commuter FFs snapped in Norfolk in the mid-90s by Paul Blezard. This photo was published in Motorcycle Sport & Leisure.

I don't know much about the bike but believe it was built in California in the late 80s. They were built by Thomas Engelbach who says there are 2*112 inch wheelbase fully enclosed ff with outrigger wheels. Both have Tony Foale front ends similar to Quantum. First bike has a 750 Honda V4 and is a completed test mule. The second has a 1100 Honda V4 and has been run at Bonneville salt flats, but is not complete.

An FT500 with Difazio front end scratch built in Australia in the 80s.

Ted Wilkins' Feet forward, snowmobile engine/CVT powered handmade project that was at Daytona in 2000. All aluminium chassis. He says it works remarkably well- far better than he hoped (and feared) He says he hates the 'scooter appearance' and is amazed/ diasappointed by the fact that it handles better than the 'conventional' snowmobile-powered bike he built before. Ted also races a snowmobile-powered hillclimber that he built himself.
http://www.eurospares.com/graphics/wilkinshillclimba.jpg