Talked to my friend, not much help. He purchases it from a salesman who told him it is made overseas. When the order is placed it is a 50 sheet minimum and comes as a 4x8 sheet (natural color). The thickness is .070", has no product name, and is very similar (material and thickness) to another friends resto house bought divider. He has always referred to it as panel board. I was given a 2x5 piece and I did the rest. The limited number of these dividers I have seen in the wild plus pictures show an original to be 2 pieces "glued" together. Here is a photo showing an original one with the thickness. 2 of the one I made "glued" together would be dead on.
Doc