50 cent airmail (first issue 1928) two values being a correctly franked multiple franking, each stamp with plate flaw VII respectively X, klr used "Saarbrücken 2 (Bhf) airmail 20. 9. 28", in perfect condition, photo expertize Ney VP (2016) : "the depicted, flawless stamps as well the postmark on the correctly franked cover are genuine. ", Michel 400. - two plate flaw on cover are very unusual!