Opole 9.2.1921 ZKr (237.7) on registered letter with mixed franking 5 Pfg / 20 Pfg blue horizontal gutter pair overprint types Ia and IIa, 5 Pfg / 20 Pfg blue three horizontal pairs overprint types Ia and IIIa provissional issue 1920, 80 Pfg purple brown postage stamps issue smelting works and peace pigeon 1920 to Doebern, arrival postmark ZKr DOEBERN (Lower Lusatia) 9.2.1920 at back, transport traces