OPPELN, 5 Pfg dark opal-green, 75 Pfg dark green, 80 Pfg violet-brown Steelworks and Dove of Peace 1920 on registered letter to Graz, double-circle OPPELN 11 12 21 * 2 * (OS handbook No. 237.27), passed German currency censorship in Dresden: yellow resealing strip / control label (OS handbook No. III A 3) and violet two-line Postüberwachungsstelle Dresden (OS handbook No. III B 2), double-circle DRESDEN 14 12 21 ALTST.7 l transit (OS No. III Bb 2), age and use marks typical of period