original c. 1940's american industrial single-sided brightly colored stamped steel "machine in motion" cautionary sign salvaged from an old st. louis meat processing complex/factory undergoing demolition. the polychrome enameled steel sign remains in great shape considering age (condition varies from one sign to the next). the vintage industrial signs were fabricated by the parker metal decorators co., baltimore, md. measures 6 1/2 by 9 1/2 inches. four matching signs available. priced individually.