I had forgotten about the dioramas. Seems that I also remember a large mural of a bombardment scene from across the river, but I guess that could have been at Vicksburg. Seems it was on the other side of the doorway in the back of the room, in the long hallway. (wasn't really a hallway but that was the feel it gave) There was something special there anyway. That's about all my feeble mind will allow me to remember.
There was absolutely no Civil War artifacts there when I went in 1990. I was extremely disappointed, nearly pissed off. I had driven nearly 800 miles to see my kids and the highlight of the trip was to carry them and an army buddy to the Pink Palace. All I really remember of it was the Piggly Wiggly, the kids interactive part, and an Eric Clapton stat hanging on a wall where Civil War artifacts had been 20 years prior.