Sounds like the drive cable is off sunroof or the drive gears are broken.

There is a manual crank in the trunk -- there is a flexible cable from the trunk to the sunroof.

My bet is the cable is broken, but I can't tell you how to get the liner out on a W123, only a W124.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!