Just a small update, I started work on the first artillery railcar, the "Kannonen und Flakwagen" which has a 7.5cm calibre turret and a 2cm Flakcannon. It's only a basic hull so far, still needs some tweaks to the armoured panels around the Flakcannon platform, doors, hatches, buffer armour, and the armoured corridor under the platform that will connect up to the next railcar in the train, the Kommandowagen - which in turn connects to the other railcar with a turret, the Geschutzwagen armed with the 10.5cm calibre turret.
Larger pics and other views in my blog here:
Panzerzug railcar "Kannonen und Flakwagen" WIP
Dan