This was available a few years ago. I’m thinking that battery mount was not a field mod.
“1943 Ford GPW Willy’s Jeep for sale. GPW stands for Government Production willy’s. It has a 134 Willy’s motor (original) Go Devel. Jeep runs good. You do not have to have a title for these old jeeps
just a bill of sale in Alabama. ”
http://tuscaloosa.craigslist.org/cto/5790695913.html