I was looking for necropolis myself and found this. I'm trying to catch up on all the main Dredd stories I've missed.
//http://www.play.com/Books/Books/4-/326371/-/Product.html?searchstring=judge+dredd+necropolis&searchsource=0
//http://www.play.com/Books/Books/4-/326371/-/Product.html?searchstring=judge+dredd+necropolis&searchsource=0