What's the best way to go about trying to find a marriage in Choctaw County? Some county courthouse staffs do not look up marriages or do any type of research. What is the experience for Choctaw Co?

I am trying to document marriage of Isaac Robertson and Eleanor Hammond. Both were in the 1850 census in Choctaw Co with their respective families and they were in the 1860 census for Choctaw Co as a married couple with children. Based on age of oldest child in the 1860 census I suspect they were married after the 1850 census and before 1852. There oldest child was 8 years old in the 1860 census.

Can anyone offer any suggestions? I would like a copy of the marriage license/certificate/etc.