Mercedes-Benz 280 SLC – First start after 14 years

Good day people, My father left me his 280 SLC! Year 76, color: green, automatic, 2nd hand & 185hp……the nice piece has been in family possession since the end of the 80s But then in the winter period the hoses or the cooler burst when freezing the liquid (I don’t know now exactly which of both) which made it impossible to drive because he lost water all the time. My father always postponed the repair until later but it never came to this…so the car stood unmoved for 14 years in a (whole) garage That also left traces (in some places extreme rust spots) So now my question: I tried to restore the car with my father. But first I have to get the engine to run. What do I have to do?? How does it look with a previous oil change? Must the tank be emptied first & new fuel filled? Please for help (because nothing is wrong & risking a motor damage) Here are some pictures: