I don't have much to help you with specifically on the Martins, but I would strongly recommend you contact the local churches and see if you can find some distant cousins living in Stokes. Often the oral history is the best, if not only, source for these families. Stokes may also have some records at the court house not found in the archives.

I do know that Davis Chapel had two black member besides the mostly white congregation. One of these was Sarah Martin who was enslaved by the Davis family and in their records I think she is the woman "Sary". Her maiden name was "Pitzer" per her marriage record to Bruner Martin who I think is the former Davis Slave known as "Brum". There marriage record is dated 1864 recognizing their common law marriage. The Pitzer name may come into things as James Davis' daughter Nancy married Lemuel Pitzer and when widowed she came to live on the Davis Plantation at Red Shoals, which on the N .Side of the Dan as you go toward Dodgetown.