Blood for the Blood G... Erm, Emprah!
For my friends on-going Adepta Sororitas / Inquisition army, he wanted 3 unique Penitent Engines. Ones that were rusty and mangled, covered in the blood of heretics. I was happy to oblige.
They all started off as regular penitent engines, then I modified each ones with assorted Imperial and Ork bits, extra tubes, and Forge World Brass etch.
The main engine was inspired by an awesome art. More pics at the bottom of the post.