I added some finishing touches, such as the windows made from spare sprue parts and an extra wall using a spare reinforced ram. I then used some green to make sure it was firmly in place and to make the gaps less obvious.
As a basecoat, I completely covered the building with merchrite red, and then washed it with devlan mud. After this had dried, I confidently based it with modelling sand, as I was sure the colour would not be spoiled. Next, I added in the silver window panes, Waaagh signs, and drybrushed pretty much the whole thing with boltgun metal.