The factory floor is silent but not empty. Dozens of workers dressed in crisp white lab coats, hairnets and matching Crocs are maneuvering dollhouse-size hand tools and manipulating minuscule parts to assemble wristwatches. With loupes to eyes, one line builds the movement–the timepieces’ quartz-powered brain. Another line does nothing but put the dials in place, while others set the hands, fix the case backs and lash the leather straps. This isn’t a clean room in Geneva or a Chinese factory in Shenzhen. These movements are taking place behind the floor-to-ceiling glass wall that separates Shinola’s Detroit he