We've definitely identified the picture of the older couple as Benjamin Pepper and his first wife, Rebecca Baker. It was probably taken in 1865 as she died in 1866. The picture of the younger couple are probably William Robertson McKee and his bride, Susan Baker Pepper. We will possibly never know the identity for sure of the couple but I have it in a frame with the other of my family pictures in my computer room. You can see the pictures on my family web page under McKee.