I fitted an exchange transfer box from Ashcoft Transmissions to my Land rover 5 or 6 years ago. Really good service and it's still working. I have also just bought an exchange gearbox from them for the same truck. Excellent service again.
On the other hand, I'm off to Transaxle Services in Halifax for a new diff for my Mk 7 RWD on Thursday. New diff fitted with all the seals bearings etc., for slightly more than Ashcrofts want for just the CW & P.