Wow, I didn't think that I would get so many responses so quickly.
Thanks for the texture tip. That might be a better method than trying to photo match each tombstone. Although having the image on the virtual tombstones will give the students the ability to get a feel for the cemetery, some of the stones are difficult to read at best. They made them out of limestone, which basically dissolves with water.
I will explore the options you suggested regarding adding text and will report back.
BTW: After seeing the locations of many of you, I am embarrased that I called our cemetery "historic."