There is lots of relevant clutch info in this
THREAD.
In the past, I have assisted a friend to resolve a similar issue to yours. We went through the process of replacing the master cylinder which did not fix the issue. Therefore, it was clear that the internal slave cylinder needed replacement. According to a well known Morgan dealer, this is a fairly common failure point. My friend used the fact that the engine needed to be removed to have the Phil Bleazey Centa modifications done at the same time. So it turned into an expensive exercise but he did end up with a better car than before he started! AND, one of the old Centa rollers was breaking up so the Centa would have needed attention sooner or later anyway.
