Look like the tailgate has been filled.
https://portland.craigslist.org/grg/cto/d/1951-willys-jeep-buick-6/6543698097.html
“fun old jeep, with good buick v-6 oddfire, nice installation looks factory, runs good, brakes, clutch, running gear all dune up a few years back and all working great. has 31×10.5×15 scorpion all season tires, newer wheels, shocks a while back. brand new aluminum radiator Washington title with new plates and tabs. no top or doors,”