OPPELN, 10 Pfg dark red-orange two singles, 20 Pfg blue Numeral issue 1920, 50 Pfg on 10 Pfg dark red-orange green-black overprint Type II a, so-called Berne issue, on insured letter (declared value 200 Mark) to Berlin Wilmersdorf, one stamp originally on reverse missing, double-circle OPPELN 10 2 21 * * b, double-circle arrival (11.2.1921) on reverse, rare franking, photo certificate Gruber BPP (2023): "An Upper Silesia rarity of rank 1."