I remember a story about him. When the 12hp limit came in, he was paid by one of the Big Four to come up with a way of restricting some of their bikes to the new limit. Leon came up with a solution that involved fitting a washer somewhere or other (carbs probably) which pegged the power to more or less 12hp. After a while, riders started coming to Ledar to have their 12hp bikes unrestricted. The industrious Mr Moss would then remove the washer and put it back in his box ready to fit to the next batch of restricted bikes. He was a very clever man.