There are alot of cemteries that are doing "Restoration" to their gravestones. Most are done by
volunteers. When I was in New Orleans in November we got to see alot of how they repair the little house crypts. It was very interesting.
These old stones are always sad for me to see. You have to remember that there was limited materials back in the 1800's to make markers with. The weather mixed with time was pretty hard on them. Luckily most cemeteries have a platt map and they do know who is buried here. Often times you will see a new marker either along side or as a replacement if there is a living relative.