What local sources have you checked with? Here are some possible places for you to check (if you have not already)...
1. Call the local library for this county and see if they have any information. You will be surprised about the people in a community that librarians are familiar with.
2. I would call the local Farm Bureau agent (not the office secretary.) This sounds like a stereotype, but Primitive Baptist congregations have a tendancy to be rural. If the agent does not know, always ask who they would suggest that you talk to the area.
Pastor Tim Mohon.