It needs some work, but original late 3B bodies aren’t easy to find.
https://houston.craigslist.org/pts/d/stafford-body-tub-and-hood-for-cj3b/7266307155.html
“Original body tub and hood for CJ3B. Quite a bit of rust through in the floor and in overall rough condition. Great for a rebuild, hunting, or buggy project. Practice your cutting and welding skills!”