1984 300D Turbo

Roof slides forward 1"- grinds on the Driver side-(is the motor in the trunk?) can feel it in the sheet metal. possibly a gear stripped- but I cant even slide it-it is firmly stuck open.
I looked in there with a flashlight- could not see anything different between the 2 sides- track is clean/unbent- nothing seemed to be impeding the slider.
This thing worked fine yesterday.
Now I cant even get the roof closed enough to drop the liner to see WTF is going on.
I am so screwed.

I need to do is get it closed so I can go away this weekend without fear of a soaking wet interior.

any and all help is immensely appreciated.