10 C. "Mercury Head" and 90 C. "Peace Allegory" definitives, type I overprint, correct mixed franking on small lady's letter "Dunkerque 8.07.1940" to Ghyvelde, arrival "9.07.1940" on reverse, perfect condition, expertised Calves, Dreyfus, Roumet, Lothar Herbst VP expert opinion (2025): "Condition faultless. Stamps known in very small numbers and therefore very rare.", Mi. 800.-