Compton also has a very high tech coating concern that we've used over the years. I'm not sure what they rely on, but there're huge exploded views of jet (or rocket, I don't know) engines that they do work for. All their header work is done out the back door and, as I remember, the proceeds go into their "coffee fund".
Almost every town has its good and bad places, and if you pay attention, you don't need road signs to declare them for you.