The rear floor might have been replaced with some diamond plating.

https://tricities.craigslist.org/for/d/willys-jeep-1949-cj3a-and/6594982114.html

“Willys 1949 CJ3A with M100 Trailer. We’ve put a lot of work into restoring this jeep. I have a canvas top and frame also. I have receipts for all parts and work that has been done. Everything on brakes has been replaced new. Carburetor rebuilt by Old Jeep Carbs. New gauges and all new wiring. New alternator, starter, exhaust, hoses, and other items. Body is in excellent shape.”