I do a lot of research on my family and other families as well. I take visits to the Essex COunty Courthouse in Tappahannock, VA. I went there to do research for a gentleman researching his family roots. I came across your post and decided to write down the information you gave on the Payne family. I went through the marriage record index and reviewed a few Payne marriages. I didn't have a lot of time so I wrote down what I could. I think this is a direct match based on what you have given. The source is Essex county marriage book with marriages from 1803-1921.
1. Page 19 line 4, December 28, 1867 Austin Payne age 25 married Mary Ann Scott age 27. They both were single and were born and lived in Essex. Austin was a laborer and they were married by Lorenzo Dow. Austin's parents were listed as William Payne and Jane Muse (maiden name). William and Jane were freed from slavery when it ended. Mary's parents were Benjamin Scott and Mary (no maiden name listed). Benjamin left VA during the war and Mary died a slave.
2. Page 39, line 15 Robert Payne is 22 and he married Martha Jones age 25 on May 15, 1875. They both were single and were born and resided in Essex county at the time of their marriage. Robert's parents are listed as William Payne and Jane Muse. Martha's father's first name is not listed but the last name is Jones. Her mother's first name is Betsy but no last name is listed. Robert is a laborer and Lorenzo Dow also married them.
3. Page 48 line 5, Lawrence age 21 married Charlotte Wood age 19 on Feb 21, 1878. Billy Payne and Jane Muse are listed as Lawrence's parents. (Billy is a nickname used for William so I believe this is still your descendant.)Billy died free and Jane was also freed. Lawrence and Charlotte were both single and born in Essex County. Catherine's parents were thomas Wood who was also freed and Catharine Lawson (maiden name) also freed.
4. Robert's wife apparently died and later remarried because he is listed as a 32 yr old widow and parents are Billy Payne and Jane Muse. He married Addie Lomax who was also freed and is a single 21 year old. Her parents James and Catherine Lomax were also freed. I forgot to write the year but it is listed on page 72 and it had to be the 1880s or 90s. I hope this helps. I would like to do more research when I have time to play around in the courthouse.