Star Hawkins was a private investigator who had as his chief resource the robotic assistant known as Ilda. The female automaton had herself possessed a sharp mental aptitude and gadgets aiding her master in various cases. Eventually, they both encountered a young woman named Stella Sterling whose grandfather created the still active robot known as Automan. While Star and Stella married, Automan and Ilda also formed a life-bond, of sorts. Star's journey back to the 20th century to meet that era's oldest superhero, Captain Comet, ties he and his allies to Earth-One.
Hugo Hazard was a detective who happened to come across the evil plans of Doctor van Thorpe, who had invented a robot to use in his projected crime wave. Thwarting his schemes and defeating the automaton, Hugh then located it about to be scrapped at sea, and retrieves it for his own new carer as a crime fighter. Although his alter ego, Bozo the Iron Man, never had occasion to meet the All-Star Squadron, though he was a contemporary of the golden age superheroes of Earth-Two like Invisible Hood and the Ray had operated. Hence, Hugh and Bozo were natives of this world as well, and simply retired when mystery men became more active.
Another metallic metahuman would appear on Earth-Two around the same time as Bozo, in the form of John Zatara's sidekick Tong who himself was transformed into an Iron Man that looked similar to his contemporary.