I've ordered lots of luthiery bits and pieces from the US and Canada to Belgium. I've had to pay duty once (via the postman at my front door) but more often they've not been bothered with.

I haven't bought an instrument from the USA but have travelled a few times with expensive instruments there. I've never been stopped at customs but have always taken the precaution to have the original purchase receipt with me to show the instrument was bought by me in Europe and is owned by me.

UK people: there are some good deals to be had purchasing from mainland Europe at the moment due to the high pound and you won't have import duty problems!

Peace

moo