The Fantasy based one is now on the "to do" list.
The 10.5cm Howitzer Comes from 30 plus yr old and now damaged Hasegawa kit as do the track Frames and the commanders Cupola.
Stowage rails on the back are scratch built, the stowage from various old and damaged kits, the ammo box is from a 1/32 kit.
Commander from ...unknown kit.
Towing rope from twisted wire, the starter handle bent paperclip wire.
Antenna made with old brush bristles.
Track sag created by Putting the tracks on then using a pin, press the track down (to create the sag) and mark the spot with the tip of the pin. Drill Little holes (I used a hot pin with a cork handle which meant removing the track) insert a length of wire and Bingo. Any adjustments (less or more sag) can be made by bending the wire with some thin nosed pliers.