Yeah, I like. I really think the beaten-up look suits the facts it's orks.
I don't think the genny looks too dirty - it just needs to be bigger! Or, it needs to be in a smaller space. At the moment, it just looks like a bit of scrap that's been forgotten behind the tower (which is fine if it's supposed to be a bit of scrap forgotten behind the tower, but not if it's supposed to 'do' something).
Good looking bit of scrap though. Looks like it might be the engine of some imperial machine. I'd advocate adding some jerry-rigged orkish fuel-feed personally, like some barrel and pipe mechanism above it, something like that. It would bulk it out, cover up more of that blank wall, and give it more of a machine-in-use feel.
Just a suggestion, feel free to ignore it if you like!
:liking the scenery cyclops:
"Well it's Forty-one Thousand Nine Hundred Sixty-nine OK -
Gotta war across the Milky Way - "
Iggius Popiscus and the Stoogii, "41,969"