Have you checked out
Garden of Shadows? They have a lot of that sort of stuff.
Also check out stuff by
pixelhate at MTS. Lots of worn doors with graffiti, grungy walls, etc.
There is also a pay creator on T$R, something-or-other-sue who does urban type build mode stuff. Can't remember the name but it has a female name like sue or suzy in it. cyclonesue, maybe?