Hi paul, the motor is back together and in great shape, just got to get the valve shim pre-load sorted.
Managed to talk to peters Wife or Daugter and she asked him where he bought the bike, he wasn't sure but thinks it was from Roger Cracknell a Montesa dealer in London, can't get hold of him yet he's in the states for the winter. you are right about the head injury, he couldn't come to the phone so she asked him some questions about the bike and he tried to answer them the best he could, what happened?
BTW I got a gallon of Castrol Competition oil, don't think it's caster based, do you know what it is.