As an overseas customer you at least don't have pay UK VAT (sales tax) like we do if you order from H's. I have an ex-pat mate in Napier who ordered a fuel tank from Sparezo and it arrived with no problem. He also told me they can't be bothered to collect NZ import duties on privately ordered items under $800(?)
If you can get hold of a guy called Tim Busby somewhere up in the North Island (he has done a lot of work with REs) he might be able to advise, or even have a set of extractors. Has the sprag clutch made the dreaded bang-crunch noise, or are you just looking to get rid of it before it does?
A.