10 C. Postage stamps issue "Merkur head" and 90 cent special edition "congress of the american legion in Paris" with hand stamp overprint in type I, correctly franked mixed franking on cover from "Dunkerque 10.07.40" to Ghyvelde with on the back arrival stamp from 11.07.1940, faultless condition, unsigned, expertise Lothar Herbst VP (2018) : "the condition is perfect. The stamps are only in very small number of pieces known, therefore are they very rare. ", Michel 1.000.-