Although the 1910 census index said Dewitt Co, John actually was in Dallas Co.
1910 census Dallas Co, TX:
Hardin, John T., h, 62, M(1) 40 yrs, b AL, NC, SC " P____, w, 55, M(1) 40 yrs, b MS, AL, MS " Tom, s, 17, sgl, b TX " Irwin, s, 20, sgl, b TX " ____, s, 32, sgl, b TX [name not clear] [Although wife's name not real clear, it could very well read Panola]
I would check with the TX State Archives, have them check that TX state wide death index for both John andson Cyrus.Often death certificates will give name of cemetery where buried, too.
Since you do not ask about Panola's family, assume you have seen her with her family on the 1860 census.