Yuri Gagarin, ‘"RECORDS FILE ON THE FIRST FLIGHT BY THE USSR CITIZEN COSMONAUT YURI ALEXEYEVICH GAGARIN MADE ON APRIL 12, 1961 ON SPACESHIP-SPUTNIK 'VOSTOK.'” MOSCOW: UNION OF THE SOVIET SOCIALIST REPUBLICS, THE USSR CENTRAL AERO CLUB, 1961’, Sotheby's