The WW1 Era German Artillery/Cavalry individual rider saddle was used in the Weimar Era as the Field Artillery Driver Saddle.  The photographs below show the individual rider saddle in use with the WW1 Era Foot Artillery "Sielengeschirr 16" Harness with Weimar Field Artillery horse teams. 

 

 

Below:  Note the Weimar Era Field Artillery piece in the photograph is a mockup or fake gun.  The box like device in front of the muzzle is a flash explosive to simulate firing for training purposes.  During the Inter-War Period the Treaty of Versailles radically reduced the number and type of Artillery allowed within the German Army.