That is a cool bike.I didn't recognize the motor,and I had a Dot dirt bike as a teenager here in the U.S.. It had the Villiers 197cc motor.
no villiers had closed down in the uk by that time (mini bullet) and also had villiers (india) ,, somehow
? enfield india found the money to design new crankcases for the old villiers engine and produce a more "streamlined" version , but you can still see the villiers heratige ?