The last time I visited, the place was in a bit of a state and many of the headstones (the graves that had them) seemed to be partly buried.
You'll find the records at Stockport Borough Cemetery - now run by the co-op funeral service. They have a large map with grave plots/names on it. You need an appointment to view it. You'll have to ask them nicely if you can't get to Stockport.
N Ches. FHS were involved in a MI survey but I'm not sure how far they got and, the last I heard, the Soc was in the throes of being wound up.