Lot 356, South Korea 1950 imperf UN flags souvenir sheet, sold for $374 July 24, 2020July 4, 2017 by Sparks Auctions Lot 356 South Korea Block 21 1950 Imperforate Souvenir Sheet, with stamp similar to Scott #121 showing the flags of the United Nations and Korea. Unused (no gum) as issued, horizontal fold at middle. Michel €600, sold for C$325 plus buyer’s premium.