No, not a GPS sat nav that's doesn't work, but eBay's Global Shipping Programme (GSP). A friend has just warned that a rare Dell 'Orto was not only refused shipping (because it might still have fuel in it 30 years after last being used) but was actually destroyed. Apparently they do likewise if they consider a package too big, which has led to vintage guitars being "liquidated" (who thinks up this jargon?).
Message seems to be that GSP generates a customs label from the listing, and that a carburettor is just a prohibited item, no questions or discussion allowed. Could you get round this using a different shipper and a seller who's prepared to fill in the custom’s paper work a little more imaginatively? Maybe, but if you get it wrong that could mean the destruction of a rare spare part. At least people seem to get their money back.
Another friend had to wait several weeks for a green frame 750SS to be released to the shipper, and you can guess how much money was tied up while he sweated it out. Personally I've never had any problems buying from the US, but their border bods are most heavy handed in the world - and that includes my experience of Iran and Iraq! I was arrested aged 18 trying to board a flight home from New Orleans because my work permit was three days out. Even they eventually realised it was more hassle than it was worth not to stick this bemused limey on the 'plane, but you have been warned; caveat emptor