Most of the headstones have well gone they were all removed in the 70s, many perished or were used for flooring around the cathedral or buried under the embankment and grassed over. What you have left today are a few stones that survived the mass clearance but they are not in the original places. Over 57,000 people were buried here. If you do find the stone its most likely not standing in its original place. I will look around on the remaining stones and see if i can see the surname you are looking for. Do you know what section the grave is in?