HINDENBURG, 5 Pfg on 20 Pfg blue overprint Type I a two singles, 10 Pfg on 20 Pfg blue overprint Types I a and III a provisional issue 1920, 2 1/2 Pfg to 16 Pfg Steelworks and Dove of Peace 1920 on registered letter to Bern / Switzerland, double-circle HINDENBURG 15 4 20 h (OBERSCHL) 1 (OS handbook No. 119.11), rare cancel, arrival (19.4.1920) on reverse, passed German currency control in Munich: resealing strip No. 16 and violet "16" (= Munich), unlisted in OS handbook, good condition