I have seen some marvelous conversions here in the states... one in particular had a rear end that resembled the rear end of a 56 chevy..
a very good friend of mine had his harley ultra classic converted to a trike, because his knees were going bad and it was easier for him to enjoy the open road.. there is a group that comes to mind that loves the trike lifestyle.. and they are called "Brotherhood of the Third Wheel". I have seen photos of their gatherings, and the variations of trikes were from the self built and obvious to the professional conversion..