I'm sure with enough notice I could arrange for Terry Winschell, the park historian, and Parker Hills, the new Ed Bearss, to give a talk or tour. Parker is in it as a business, so a fee might be required, but he is awesome!
It could be a whole campaign tour if enough time. Or at least Champion Hill, Raymond, Vicksburg. Some great sites down toward Port Gibson, but would need some travel time.
Grand Gulf State Park, Windsor ruins, Bethesda Church, Rodney, etc.
John