INTER-ALLIED COMMISSION - PRESIDENT'S OFFICE, 5 Pfg on 20 Pfg dark blue, overprint type I a, double printing of numeral 5, provisional issue 1920, on philatelically inspired local letter to Oppeln, double-circle OPPELN 20 3 20 * 1 b (OS handbook no. 237.11), violet double-circle official seal COMMISSION INTERALLIEE DE GOUVERNEMENT ET DE PLEBISCITE DE HAUTE SILESIE - CABINET DU PRESIDENT (OS handbook no. 1.0.b) on reverse, envelope vertically folded, otherwise good condition