50 C. Chamber of commerce stamp, about French postal stamps for the 6 Fr. Postage supplemented mixed franking on cover from \"Batz sur Mer 9.5.45\" to Pornichet with arrival cancel from 11.5.45, the additional franking got the hand stamp overprint \"LIBERATION\" since the letter after the ceasefire was mailed, the corner margin piece the chamber of commerce stamp carries on the margin of sheet the first day postmark of the issue from 9.4.45, expertise Lothar Herbst VP (2020) : \"the condition is perfect. \"