Contact Riverside Cemetery. The man who works in the office is a wonderful person, their filing system (cards) is efficient, and the cemetery is beautiful. If everything was filled out on the card, you may be able to find name, address, dob, dod, sometimes they have the cause of death, date of burial, and (perhaps) the name of the person who placed them there. When we went looking for gggrandparents, the man pulled the cards for all folks buried in that "plot", and we were thrilled to learn that a missing ggaunt and gguncle were buried there, WITH NO STONES. Hope they can help.