10 C. Postage stamps issue "Merkur head" and 90 cent charity issue "75 years Red Cross" with overprint in type I, correctly franked mixed franking on cover from Dunkerque 1.7.1940 to Ghyvelde with on the back arrival stamp from 02.07.1940, 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. ", Michel 1.000.-