Nathan Elkins has commented on two groups of coins being sold as coming from detectorists in England. See: http://coinarchaeology.blogspot.com/2009/05/having-cake-and-eating-it-too.html
Though I disagree with Nathan's tone and some of his conclusions, I do agree with his main point that artifacts found in the UK should be properly recorded and exported consistently with UK law. In this regard readers should note that the Treasure Act does not necessarily require reporting for individual coin finds , but that the law does encourage voluntary reporting of all finds under the Portable Antiquities Scheme.
I suspect it is quite possible that there was no legal obligation to report the coins if they were found individually. I also suppose it’s possible that the coins were reported by the finders under PAS and then sold to these two dealers, but I readily admit that might not be the case. I also suspect that the US dealers or the finders may have not sought to procure an export license for the coins, though it is possible that the individuals involved might have not realized that an export license was required under UK law.
In any event, the PAS publishes a nice summary of "advice for people buying archaeological artifacts from the UK:" http://www.finds.org.uk/treasure/advice.php
UK authorities also have issued this guidance for the export of cultural goods, including numismatic items: http://www.mla.gov.uk/what/cultural/export/export_licensing
From my perspective, I would be happy if US Customs was more forceful in helping the UK to enforce its fair laws rather than in effect underwriting enforcement of Cyprus' unfair, nationalistic laws by detaining any and all designated coins of Cypriot type based on the erroneous assumption that they "must be stolen" from Cyprus.