The Society for German Genealogy in Eastern Europe (SGGEE) has produced a 2017 desk calendar featuring photos of Germans in Poland.
This project was done in collaboration with one of their members in Germany, whose father was an editor and photographer among Germans in Poland and Volhynia early in the 20th century. His surviving photo archive has been donated to the Herder-Institut in Marburg.
SGGEE has these calendars available for sale using PayPal in North America and invites anyone with an interest to visit their website for further details. It makes a quality gift for anyone whose German ancestors lived in Poland in the 1930s. Please note that this webpage also contains information in German about where to purchase copies in Europe.