50 C. Postage stamps issue \"peace allegory with new value 50 C. \" with overprint in type I, variety \"inverted overprint\", properly franked multiple franking on cover from \"Ghyvelde 11.07.1940\" to Dunkirk with reverse arrival postmark from \"12.07.1940\", faultless condition, expertise Lothar Herbst VP (2019: \"the condition is perfect. The stamps are only in very small number of pieces known, therefore are they very rare. Multiple franking of this issue with inverted overprint are extremely rare. \", Michel 2.300.-