My l/h drive shaft is quite corroded where the hub nut attaches, I think if we need to do any intervention on that side requiring hub nut removal the threads will no longer exist, where is the best source of a "good quality" reasonably price spare for future use ?

AUTODOC 

Secondhand genuine from ebay.

Photo of perceived problem?

Seen when we changed the front shock absorbers last week (can be done without disconnecting hub nut), used genuine is a viable option