Help attaching Window glass to Regulator

[regisphilbin]

I have a driver side window on a 1978 450SL that detached itself from the window regulator. I was wondering if I need any type of adhesive to make sure the glass stays in the rubber tracks. So far, I've just pushed it back into the tracks (about 1/2" of the glass is in the rubber) I would like to avoid taking the door panel off frequently.

Also, as shown in the pic below, I guess the previous owner's had some repairwork done to the window mechanism and they "cut" part of the door frame . Without the stiffness, the window mechanism seems to move around when being actuated. I was planning on welding (or bolting) a backing plate. Any other suggestions or advise?

Thanks,

Regis