A neighbor has a 77 Chevy half ton that he has kept primarily to lend to others (a pickup truck is one handy item). The cab is rusted badly. I drove it in the rain once and the tires kicked up splatter through the floorboards and it got all over the door panels. Luckily I was wearing large boots at the time and could block the majority of the wash from blurring my vision. Rust like this has affected the structural integrity of the cab and the doors don't close very well. This is of concern to the owner as he feels it is a safety issue and increased risk if he continues to loan it to people. The truck only has 60,000mi on it and runs perfect. Should he attempt to replace the cab? Is there someone who sells new ones, or a good source for used ones. How much hassle would this be?