Have you tried looking for a marriage record at Harrison County Courthouse?
They have them waaaay back. There used to be a man who answered inquiries
received by the courthouse and would do minimal research. Don't know if
they have anyone like that now, but it's worth a try if you can't go there in
person. I was there about 10/12 years ago, and was allowed to browse the
dusty room containing hundreds of old marriage records going back at least
150 yiears.