Hi Grumpy
Sorry, my post wasnt specific enough and I may have misled you. Its a Rover 45 (Scott Bonner !) red with the flash black plastic cover over the clutch assembly and shaft. One of the later ones that were made I think.
The plastic thrust pad (is not a bearing) or a part of the clutch proper sits in about the centre of the shaft in teh clutch fork assembly and when the clutch lever is activated / deactivated  "pushes or releases " the clutch body (chain side) to disengage / engage the clutch. I would say its the sacrificial part that wears over time. I think there is a oil lube point in the black shield that sits over it.
Talk of taking the clucth and unbolting the motor scares me a little to be honest..This follows roughly along the line of a previous thread except the motor wasnt being removed.
Thanks