Buying the part is easy.
Fitting it is not quite so.
There is a lot of labour time involved, maybe quicker if you can build one on the bench and swap the complete housing but not much in it really.
Remember - the LATER cars (that this diff on eBay is for) have welded crownwheels.
These must be machined off to accept this part and that is NOT a cheap or simple task.
The sellers don't tell you this....
Early cars like my 56 plate manual had the straight forward bolt on crownwheel assemblies, meaning a cheaper/faster job.
