Archer Milton Huntington was a U.S. Railroad magnate who compiled a collection of 37,879 European coins. He is known to have had the most extensive collection of Visogothic coins, early medieval coins more than 3,000 bronze and silver Roman coins, 400 roman gold coins spanning the entire history of Rome, and about 4,000 coins of medieval and later periods. The collection included the entire history of Spain from the 5th century to the early 20th century in stamped gold, silver and gold according to Lee Rosenbaum.
The collection included a unique X Excelentes coin minted in Segovia with its famed aqueduct mintmark.
Upon his death, he donated the collection to Hispanic Society of America who loaned the collection to the
American Numismatic Society. When the Hispanic Society ran into financial trouble in 2011, they recalled the loan from the ANS and engaged Sotheby's to sell the entire collection in a sealed bid auction on March 8, 2012. Sotheby's estimated the collection to be worth $25-$35 million. The collection did not garner a satisfactory bid.
After the failed sale, Jesus Vico, a coin dealer in Madrid auctiond 1,000 of the coins and an unknown U.S. coin buff bought 10,000 coins from the collection and loaned them to the ANS so that the material could be researched by scholars and the body of knowledge of the history of these coins and their attendant lived history could be studied.
A coin that was not included in the 10,000 coin sale to the U.S. coin collector nor the 1,000 coin Vico sale in Madrid was a rare XXXXX (50) Excelectes coin that is 66mm wide and 176 grams of gold (5.65 troy ounces) with the Sevilla mintmark. Some have said that it is the largest and most important European gold coin ever struck. I found obverse pictures but none of the reverse. Does anyone know where or to whom this coin went?

