A 17-ton trove of silver coins recovered from a Spanish ship sunk by British warships on a voyage home from South America in 1804 was set to be flown Friday from the US to Spain, concluding a nearly five-year legal struggle with the Florida deep-sea explorers who found and recovered it. Odyssey Marine Exploration made an international splash in 2007 when it discovered the wreck of the ship, believed to be the Nuestra Senora de las Mercedes, off Portugal's coast. At the time, the coins were estimated to be worth as much as $500 million to collectors, which would have made it the richest shipwreck haul in history. Spain's ambassador to the US, Jorge Dezcallar de Mazar, was expected to watch Friday when two Spanish military planes take off from a Florida Air Force base with 594,000 silver coins and other artifacts aboard. The Spanish government requested a high-security operation, and key details arranged with US authorities weren't disclosed. On Thursday, the Peruvian government made an emergency appeal to the US Supreme Court seeking to block transfer of the treasure to give Peru more time to argue that it is the treasure's rightful owner. Peru said the gold and silver was mined, refined and minted in that country, which at the time was part of the Spanish empire. The appeal was directed to Justice Clarence Thomas, who did not indicate when he would respond. US courts had previously rejected claims by descendants of the Peruvian merchants who had owned the coins aboard the Mercedes. “Peru is making the same arguments that have been rejected at every level of the US courts,” said James Goold, a Washington attorney who represents the Spanish government. “