Urgent- While I have problems with retraction and rear
tilt, I currently can not get the back of the sunroof to
seat, from the rear tilt position, any suggestions?

You can do it manually, there should be a little hole under (actually over) the dome light housing, it takes an allen wrench like tool, and you can manually close it this way. I don't know the specifics for your car though.

DOES THE SUNROOF OPEN (SLIDE BACK) AND CLOSE? I HAD SIMILAR PROBLEMS ON MY 86 420 SEL. MY SUNROOF WOULD NOT OPEN OR CLOSE, BUT WOULD TILT UP. I WOULD TRY TO CLOSE FROM THE SUNROOF BEING TILTED UP, BUT WOULD ONLY HEAR THE MOTOR RUNNING. AFTER, I COULD PUSH DOWN MANUALLY , AND IT WOULD SEAT IN THE CLOSED POSITION. I THOUGHT THE CABLE WAS FAULTY, BUT IT TURNED OUT THAT THE BRACKET THAT ATTACHES THE CABLE TO THE SUNROOF PANEL WAS BROKEN- A 3.50 PART. MUCH BETTER THAN THE 55.00 CABLE.

HOPE THIS HELPS

David,
the sunroofs with the motor in the front of the car (like in your C class) are only used since the later models (W202, W210). The older models, as the W126 S class, had the motor in the trunk.

I think that your sunroof has something broken in the tilt system (as constellation wrote). It is something that happens rather often on the older sunroof systems.

greetingz,