Isn't that trapezoidal piece in the picture the rear subframe mount, not a differential mount? The two large bolts attach to the subframe, not the differential. The differential is attached to the subframe via 3 cylinder shaped mounts that each come in two pieces.

Still, I also lift my 560SEL from the differential. The shop manual says its ok for this car which is good enough for me. I then rest the car on the rubber mounts using flat-top jack-stands. It was very difficult to find someone who still sells flat-top jack stands. Mine came from AC Hydraulic in Denmark. The rubber top on the jack stand has some give to it so that the hard rubber mount of the car sinks in. Very safe.