If you can get the ground wire under a screw in the back of the box it gets you started. Then a self grounding receptacle will work.
Did they, at least. get them all twisted together to continue the ground from box to box?
If you can get a 1/2" or so, you can also use one of those push on connectors we have been talking about. Then you can pigtail on as much wire as you need to tag the box and get to your devices.