I can tell you for a 300SD (1984 also 126 body). To change the oil you dont need a lift or even a jack (assuming the car hasnt been lowered). There is enough room under the car to get an oil drain pan under the engine, and remove the drain plug if your willing to lay on the ground. If you suck the oil out from above you dont even need to get on the ground (again check the archives).

Good luck
Paul