Your truck doesn't look that bad. The engine compartment look clean. I think, not sure, that the vent windows are held in by the rubber around them. I know someone one here knows so they will correct me if I'm wrong. As for the two carbs., and exhaust I think I would probably get the engine in top shape first. Just my opinion. Take your time and enjoy the project with your Dad. Sure wish mine was here to help me. Take care, Steven