Insurgenten-edition (so called. Korfanty issue) 1921, 10 F red, 20 F dark gray violet two single stamps, 40 F dark gray green, 60 F black gray blue thick paper two single stamps imperforated on special delivery letter from Czerwonka to Knurow, ZKr CZERWONKA 20.6.1921 (058.2), arrival postmark ZKr KNUROW 21.6.1921 (149.2) at back, cover with affixed spots at back