500 Fr. postal stamp with 371 / 72 and 369 on properly franked value cover "SAARBRÜCKEN 2 14.5.57. - 12" with arrival postmark "SAARBRÜCKEN 2 14.5.57 -20", photo expertize Ney VP (2016) "the stamps on the correctly franked, transported cover are in perfect quality. " Michel 400.-