FOUND ONE
New Morgan master cylinder supplied by
https://www.m3wservices.com/ in France. Good servivce and fast delivery.
Arrived this afternoon and now fitted - job would be easier with a second pair of hands.
No need to dismantle too much as the cylinder can be accessed and removed through the inspection hatch.
Clutch action now as smooth as silk. Interestingly the biting point seems higher.