Hiya Mark
Not that I would suggest this

But, it HAS been known.. that some seriously unscrupulous people..........

errr.. find a marina that has closed in the EU - or changed hands, and, a company of the same ilk in the EU.. photocopy an old bill to prove they were their, and, vat receipt for the sale of the boat in the EU.. or make one up in the name of such a genuine now defunct marina or company... edit with paintshop pro.. then apply a mild cold tea solution to age the paper..
Problem solved.. NOT of course, that I would personally recommend doing it this way so as to be logistically untraceable...

BUT................. hmmm