An incredibly rare and valuable stamp stolen right out of its exhibition frame at a 1955 convention resurfaced this month in New York and has promptly rocked the philatelic world. "Inverted Jenny" stamps are considered the most famous in America: A printing accident in 1918 produced a single sheet of 100 of the stamps, each featuring an upside-down Curtiss JN-4H biplane, NPR explains. In 1955, someone swiped a block of four from the collection of Ethel Stewart McCoy, whose father was a Dow Jones founder. It is "one of the most notorious crimes in philatelic history," Scott English, administrator of the American Philatelic Research Library, tells the AP. The stamp was submitted this month to New York auction house Spink USA by an unnamed man in his 20s who hails from the UK and says he inherited it from his grandfather; it's unclear if he knew it was stolen.
A press release from Spink USA states that the inverted Jenny was "determined to be position 76 in the pane of 100 subjects"—the one in the bottom right of the block of four stolen. Identification took some sleuthing: In a long-ago attempt to disguise it, the stamp "had been reperforated at right and most of the gum was removed, so the pencil position numbers written on the gummed side had been lost." Positions 75 and 65 turned up in 1958 and 1982, respectively, and the new discovery leaves only one of the four stolen stamps unaccounted for. (In 2014, a dealer offered a $50,000 reward for the missing inverted Jennies.) The American Philatelic Research Library at the American Philatelic Society was given rights to the stamps by McCoy, who died in 1980, and is working with the auction house to take possession of the stamp. (By one measure, this stamp is the most expensive thing ever sold.)