50 C. Charity issue \"unemployed children\" with overprint in type I, variety \"inverted overprint\", properly franked multiple franking on cover from \"Ghyvelde 8.07.1940\" to Dunkirk with reverse arrival postmark from \"9.07.1940\", faultless preservation, expertise Lothar Herbst VP (2019: \"the preservation is perfect. The stamps are only in very small number of pieces known, therefore are they very rare. Multiple franking with charity stamps, to boot with inverted overprint, are extremely rare. Michel 1.800.-