Henry Allen Pentecost is son of George W. Pentecost and Susannah Ward. George is son of Scarborough Pentecost and Mary G. Weathers. Mary is daughter of Nathan Weathers and Nancy Zills. We've Corresponded on Nathan's descendants before.
I have nothing further on Nannie Koonce's parents except the 1860 census I referred you to and the fact that Sarah was buried in the Pentecost graveyard at Seven Pines, MS.
Henry is buried in McCrosky cemetery, don't know why he is not buried by either wife.
My bunch of Weathers changed their name to Withers when they moved from VA to TN. Or perhaps the people in TN mis-understood the VA dialect, and changed it for them. But it stayed Withers thru moves to MS and then to TX. But I found no connection between the Weathers of Sussex County and the Withers of other parts of VA.
anything else I can help you with on the Mississippi Pentecosts or Nathan Weathers descendants, just holler.