The scenario for the assault on the Polish Post Office in Danzig called for a number of specialized units in the German order of battle, such as the Steyr ADGZ armoured cars. It also called for quite a number of artillery units that would be placed on the table top, something that rarely happens in our games. The Germans deployed a total of two 75mm Infantry Guns (7.5 cm leichtes Infanteriegeschütz 18) as well as a 105mm howitzer (10.5 cm leichte Feldhaubitze 18M). I had one of the former that I bought years ago when planning out a Dieppe scenario, which I have since painted, but I couldn't justify the cost of the additional guns which are likely to only see action in the streets of Danzig.
Here are some stills of the two types of artillery taken from film footage of the actual attack.
It was time to do some scratch building. Materials for the 75mm Infantry Gun were balsa, cardboard, paper, and bits of cork. The wheels were salvaged from some old Airfix HO Scale French Napoleonic Foot Artillery