Date registered: Dec 2005
Vehicle: 560SEL 560SEC 300SEL E320 Cab. MB Metris Van / 300TD 300TE 300SDL, 300D, Unimog 406 (Gone)
Mentioned: 4 Post(s)
Quoted: 293 Post(s)
Admittedly, I have not parsed every detail of your story. But, then, these observations are helpful but not reliable. Ask your mechanic. He will probably ignore everything you tell him until he sees it for himself. One fact for sure, your car overheated.
Except for overheating that only comes at idle, standing still, warm out, car in Park, mostly a MB V8 does not need a fan at all. If your facts are that your car has not overheated when moving, spend as much as you want on the fans. Otherwise, thermostat, air pocket, radiator. In that order.