Thanks Bill, lovely isn't it? I have seen it before and the Velocette V-twin called a Vulcan, both really nice home-made specials.
I once met a man who raced Leaping Lena which was a Panther sidecar outfit, but sadly I can't remember a lot of what we talked about. I do seem to recall it was known as 'leaping' Lena due to it's inability to keep the front wheel on the track! Good old thumper torque.
Ian