Orientation of on/off switch, button and cable

I'm working on an iPad 2 that was dropped. The drop requires the replacement of the volume control, on/off ribbon cable.

I've got most of the ribbon cable installed but am stuck at the on/off switch and need to know the correct orientation of the metal switch plate and button.

I have the button installed on the plate correctly but am not sure if the ribbon feeds from the top or bottom. Also, the button can go in two different ways-the metal piece on the back of the button has a plastic stop. Should it stop the metal piece from hitting the bottom or top of the case.

Thanks,

Ed