I lost the diff recently and the whole engine has to come out to get the gear box off (25hrs labour) the AP clutch was also replaced while it was out and that cost about £300.
you have to take the gearbox out to change the thrust bearing,its false economy not to change the lot whilst in.I own my own garage so do my own repairs,not done clutch yet but looks a mare alan.
With the engine running at tickover just listen...now depress the clutch pedal. If a lot of the mechanical rattling goes away you've got a noisy thrust bearing.