Back in the early 60s I was lent one of these and took it for a trip up the M1. No speed limit in those days so kept it near the ton most of the way. On reaching the other end amongst other things found the rear number plate had vibrated off and the rear light was hanging on its wires. Its speed was impressive,notice no mirrors then but as we didn't wear helmets was easy to look back and your ears also helped to tell you what was behind you. Not wearing helmets was far more pleasurable for riding but the downside was broken heads in hospital wards giving motorcycling a bad name.
One of these was my pride and joy in the 60s. I had the clubman version,once you had learned to kickstart this bike you were a biker. I still think its looks were better than todays superbikes.Something to do with the amount of visible engine and lack of streamlining and plastic,a single pot engine much more satisfying than todays high rev fours