I'm no expert, but this is either very cheap or a rep.
http://www.ebay.co.uk/itm/Audemars-...136?pt=LH_DefaultDomain_3&hash=item3f4e940138
http://www.ebay.co.uk/itm/Audemars-...136?pt=LH_DefaultDomain_3&hash=item3f4e940138