Bed wood is not a problem. You can buy the complete setup, or make your own. See
Mar-K out of OK. Rust in the cab corners is SOP for these trucks. You can buy new cab corners, cut the old ones out, and weld the new ones in or fabricate your own patches from sheet metal. I would check those paint bubbles closely. Look under the truck with a flashlight to see if the rust is more extensive than the paint is revealing. That may help drop the price. Or, it may help you decide to pass on buying the truck.