KREUZBURG 17.12.1920 single circle (OS handbook number 172.1) as well cork cancel (in the OS handbook unlisted) on package card with 50 Pfg grey 2 single stamps at back and 75 Pfg dark green each once on face and at back smelting works and peace pigeon 1920 to Prenzlau, arrival postmark ZKr at back, more exact identification impossible, time typical traces of age and usage