30 C. "Mermoz" and 70 C. "Straßburger Münster" with overprint in type I as correctly franked mixed franking on cover from "Dunkerque 2. 7. 40" to Bourbourg with reverse arrival postmark from 3. 7. 40, the left stamp with perforation fault top right - otherwise in perfect condition condition, signed Zierer and certificate with photograph autumn VP (2014) : "the stamps are only in very small number of pieces recorded, so that they very rare are. The postmark "Bourbourg" is very rare. ", Michel 1. 000.-