Clutch Slave Cylinder
After a few journeys I noticed that I had to top up the clutch fluid by the equivalent of a millimetre or so within the reservoir.
I took a look underneath while replacing the engine oil and filter and noticed that the slave cylinder was wet and had obvious signs of leakage.
After making some enquiries I was told the best place to buy a replacement part was TVR Parts Ltd, providing the unit had not had the pipe modified. If it had it would mean that a Land-rover part would fit instead, apparently a common modification.
I will take a look at completing the repairs over the winter when the car will come off the road.