Thankyou to you both,
As you can tell I am a novice on the web. I tried to send pictures but I was not successful.
But the info you have given me sounds right, the bike frame is 1965 the eng is from 1963.
The gear you show me dr6t looks right as if it would fit is there a part no for the other drive to match, in case mine is wrong...and as the drive does not have a bush is it just held in by the pin.
Many thanks I think we are getting there.
Ian.