If you haven't checked with local and state Historical Societies, do. Sometimes they have copies of old records that have been lost, missing, fires, etc. They usually also have monthly journals that may have genealogically done some of these families in the past and they maybe within the journals.
Also Check with local History museums, and County /State level museums and Historians. Check with local colleges within their history depts, genealogy dept, etc each of these places maybe a stretch but if this was an old cemetery there is bound to be someone or someplace that documented it, and its first inhabitants. Also check with local mortuaries, someone at one of them, may have info on the cemetery, who owns it, or owned it etc.
If all of this brings nothing and you know there are unmarked graves, this needs to be brought to the attention of Historical Societies for 1. protection from destruction, and 2. Attention to National Historic Register w/questions about why some graves were moved that had names but others were just left unmarked and uncared about and what can be done to find out who these grave sites belong to and protection by fed level Historical Register
Starting an online platform to bring this to the attention of local ppl whose families may also be buried there in unmarked graves, and requesting exhumations for dna testing to match the dead to the local living is extreme, but might work if there is enough interest and pressure put on the local/county & state. just some thoughts hope some of it helps
what is the name of the cemetary, and where was it originally located, please & thank you
oh and check with the local clerk of courts. you'd be surprised what they have in paper and on microfilm in some locations