Look no further since I have a copy of the original deed of manumission for 1791 and copy of the slaves with last names.
There were about 483-509 names. I was able to locate about 40 of my family members listed and I would be happy to share it you or anyone else out there that like a copy. One thing to keep in mind is that all
the slaves listed did not get their freedom all at once. This was to be done over a period of about twenty years. You should also keep in mind the fact that there were children being born to the enslaved persons while they were waiting to get their free. No one has to my knowledge ever did a study to see how many of them every really got their freedom since Robert Carter died in 1804 and they were divided up amount his heirs. But having a copy to search for your family is a start maybe you will have as much luck as I did.