Found one of these low mileage in a barn a couple of years back. They're stone reliable and have a dual range transmission, auto clutch, and will climb the side of that barn. You can restore one pretty cheaply using NOS and Repro parts from e-bay.
It seems Savannah has a surplus Armored "Humber". Yes, you read that right. It's NOT a Hummer but it would seem to be a 1957 British built APC of some type with a Rolls Royce motor. Check it out.
Here's another I recently read from the DeKalb Library systm. It's very current events and very realistic.
http://www.amazon.com/Survivors-A-Novel-Coming-Collapse/dp/1439172811