Building the inquisitorial mobile fortress starts with the track segments. Anything 40K scale would be waaay too big and anything in epic would be too small (except perhaps old capitol imperialis tracks but I'm not seeing any of those in my bitz box...)

My solution is to start by gluing two small imperial track unit wheels together with a spacer. They are connected by a rod, that rod has the spacer placed over it. Glue in place.