In the late 1940s when Upjohn was building their Portage manufacturing site, it was critical to model the production layout in the giant manufacturing building- (Building 41, which had 1.5 million square feet of space. Upjohn had over 5,000 small models of equipment and people created so they could model every production process in the building. This was to ensure enough space, equipment and people were allocated to each process. Individual models were made from metal, wood or plastic. At an estate sale in 2019 I found a representation of a Building 41 Upjohn packaging line using those models from the 1940s. The piece of wood you see is 13 x 6 inches and it has a plexiglass cover. This is not an official company model used in the 1940s but probably created as a memento of that era. There's a January 1949 Upjohn News article here that gives more information and some photos of the full model in the company museum during the 1950s or 1960s. The last photo is from the January 1950 Upjohn News magazine.