Years ago I made a Nurgle Baneblade / Hellhammer that had an additional turret to make it a Plaguereaper.
Recently I found this beast in my storage room and decided to bring it back to life and auction it off on eBay. At this point the paint job is almost done, but I figured I'd show some WIP pics I dug out of my archives from when I built the thing.
The tank was built with the intention of being either a Baneblade or Hellhammer, and I built a extra fuel drums and a separate turret with a HUGE heavy flamer that counts as a Plaguereaper cannon.
I created the chaos trim using the same technique that I showed in this tutorial: http://eyeoferror.blogspot.com/2013/01/creating-complex-styrene-plasticard.html
Note: The chaos champion in these pics is not the same as the final model. Also, these pictures are 7 years old and not up to my current standards.