Opole 10.9.1920 ZKr (OS handbook number 237.19) on DR postal stationery service postcard issue for Prussia 10 Pfg carmine 1920 (German Reich Michel number DP 4) additional franking OS official stamp 20 Pfg violet ultramarine (Michel number D 4) as local postcard used, rare and unusually postal stationery follower, time typical traces of age and usage