Hi Jonny,
I'm also UK based and have had nightmares trying to arrange shipping from here.
Even Parcel companies that'll ship/insure deliveries into the UK seem to refuse to carry watches out.
Some also insist on seeing the item before its wrapped to make sure its what you say it is, (or isn't).
Believe it or not the best I've found so far has been Royal Mail Airsure which is tracked and relatively inexpensive - only my experience though...
AndyO...