I managed to find some spare time to invest in finishing this long project. I started out airbrushing the entire building with consecutive layers of Shadow Grey, Fortress Grey, Skull White. I like Shadow Grey and think the combination has the right concrete look to it. After this job I airbrushed a rather astonishing amount of wash around burned out and bomb-shelled windows and other features (and where fancy took me). All I can say is long live Vallejo for supplying these huge barrels of wash (black and sepia for those keeping score).
After allowing gratuitous time to dry I used alternating combinations of Black and Sepia ink to weather crevices and to darken the lower side of the building a bit (and to give the pipes a bit of character). Lastly I painted the roof Boltgun Metal followed by a sepia wash with an edging of Devlan Mud. After that I applied rust colored weathering powder to finish. To finish off I painted the outside of the base with brown from the scenery painting kit followed by a drybrush of Bubonic Brown.
To round it off I applied Scorched Grass on the base (to fit this project in with my other scenery). Around the pipes I applied dead grass (to give it hint off toxicity). Then I wondered for about ten minutes why on earth I started out drybrushing the base (as that paint job is now hidden beneath the flock ).
Anyway enough talk, these are the pictures.