The Geier Typ 100/S3 RT (DKW 100ccm, 3,5PS) has been presented at the IAA 1939.
From 1939 on, Geier was no more allowed to produce motorcycles by the Schell-Plan. Nevertheless they produced the type 100/S3 RT until 1941, now called "Behelfslieferwagen", "ohne Bezugsschein mit Gummi". As written at the advertisement, you have sent with your puzzle.