The fuel tank & fuel lines look OK, with no significant rust anywhere on the truck. If access is ever needed inside the fuel tank, it's much safer, quicker, & cheaper to cut a hole in the floor under the (glued-down) carpet, instead of lowering the tank from the truck.
IF THE IMAGE IS TOO SMALL, click it.
Supply & install custom fuel tank access hole cover plate (includes peel cargo area carpet up) $200