The second hand 2.88 diff that was fitted a few years ago is becoming increasingly noisy. 

In the opinion of at least one local independent, it is a worn crown wheel and pinion and the only solution is replacement.

Before I head down the factory unit route (£1000+), has anyone got an OK one they would be prepared to part with? 

It's going into my Daimler Double Six (1984) but one from a V12 XJS would work just as well.