It might look like a hulk and a pile of rust but, apart from the diff, how is the frame?? As a WIAUT (While I am under there) exercise, check the frame to see if it is still all in one piece and no damage or rust in places like where the body mount bolts come and go. Good stock G body frames can be valuable, particularly to builders north of the Mason-Dixon and located squarely in the middle of rust belt country. Owner might cut you a huss if you make an offer on the rolling chassis; get it back to your garage or shop and strip it at your leisure. Or, maybe a trade, parts for a load of granular B or gravel to fill in that hole. (Hey, you never know what someone will take by way of an offer) Also, the motor might be dead and gone but take a peek for all the brackets and associated bits. Been folks from time to time on this forum looking for the odd item; puts a few bucks in your pocket for either parts you need or a brew or two for after the fight (to remove the valuable parts).
Nick