And here it is: this actually is a Winselmann Hera. Manufactured by Gustaf Winselmann in Altenburg in Germany.
This machine was distributed by Eduard Rühl in Nuremberg. The machine was found in Nuremberg and acquired there by the previous owner who kept it for around 50 years before kindly giving us care of the machine.
Deutsches Reichsgebrauchs Muster, meaning a registered design of the German Reich.