2002 C230 Kompressor

Hi,
Only 6 months ago, I replaced the control unit (or whatever it's called - the unit embedded in the ceiling with the dome lights and sunroof control), because the glass was opening fine, but the screens were stuck closed. It did the trick, and everything has worked fine since.
Now, the screens are stuck in the open position, and if I try to either open or close the glass part, there's a loud clicking noise, which I assume, is the drive motor missing gears.
I took out the control unit and watched the motor (on the left) jump as it clicked. I guess the other motor (on the right) is for the screens, as it does nothing.
I plan on looking for a replacement motor at an auto salvage place.
does anyone have any recommendations or advice?

Thanks