I posted my video of the grinding to YouTube linked below:
https://www.youtube.com/watch?v=iZa_8410t_o

I've since read up on the issue and agree with recommendations to leave the glass pane non-op for now. The sunshade was what I REALLY needed to get working and that problem is solved so I'm much happier with the current state of it.

I'll continue researching and reading threads detailing the work involved in taking the roof apart and fixing it.

If anyone knows of other good threads for repair or replacement of the cable drive components please chime in. Thanks everyone for the help so far.