When the Upjohn Portage Manufacturing site was being planned in the mid-1940's, it was important to make sure every manufacturing process  would actually fit inside it. There were no computers in those days so the planners had over 5,000 small models of equipment and people created from metal, wood and plastic. They literally modeled every production process in the building. 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 one created by a company craftsman as a personal memento of that era. The full story of the Building 41 model is at this link.