Pretty sure that the rider is Graham Rhodes who worked for Silks at the time and went on to be a fabulous classic racer. His son son, Sam, rides trials occasionally (very well) and a few months ago competed on this bike at the so called Clifton easy trial and probably would have won if it was running right. I had a quick ride after the trial and considering it's age it is quite a good machine, but I would love to try it with the swinging arm in the conventional position to see how it compares to the setup it has.