I've read Level 7 but it's been years. I havn't been able to find it in my boxes of books. But it's there. My new favorite is "World Made by Hand" by James Howard Kunstler. The protagonist is an old time fiddle player in upstate NewYork. Two nukes destroy LA and DC. After that all oil shipments are stopped to the US and the electric grid goes down. People have to go back to farming and the barder system.