Some gas shocks (don't recall the makes) are designed to have the tube on top and the rod on the bottom. I just did front brakes on a 1979 280CE and the front shocks were like this, the top and bottom mounts were different and there was NO way to mount these shocks otherwise. There may be 'normal' shocks availible for your 190D but I don't believe the ones now on the car, are installed wrong.

Happy Motoring, Mark

__________________
DrDKW