1872, Mixed Franco-German franking on the front of a letter to Paris made with German stamps Brustschild n°4 + n°6 cancelled cad Mulhausen of 19 Marz associated with 3 French stamps of different issues with Bordeaux Y&T n°48 + Siège n°37 + Lauré n°28 cancelled cad bleu Paris Etranger of 20 March, exceptional combination likelymeznt unique, Menozzi certificate (2018).