FRENCH FIELD POST, black-and-white picture postcard 1920, postage-free field post from Gleiwitz to Tindja/Tunisia, single-circle TRESOR ET POSTES * 24 9 20 * (184) * (OS handbook no. FFP1a), single-circle arrival TINDJA 9 30 4 -10 20 TUNISIE, unusual rare destination, age and use wear typical of period