I remember Vance Astro of the Silver Age GOTG meeting his teenage self in the original DEFENDERS and giving him a carefully-edited explanation of the dystopian future that had been experienced on his Earth. Including the Cyborg Wars that had given rise to the original Deathlok! Which means that Earth-691 and Earth-7484 were originally one and the same.
But, of course, they have long since diverged thanks to Captain America (Steve Rogers) having prevented the world-wide Nth projection that eliminated all the resident superheroes of Earth-7484...originally.
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