You don’t remember? Well good because if you said you did you’d be a dirty rotten liar. There was no live-action FF show in the 1960s but that doesn’t mean there shouldn’t have been one especially if it would have been anywhere near as cool as the one that has been imagined by the owner of the site dedicated to the show that never existed.
According to this site the FF show ran from 1963-1964 and featured Russell Johnson as Mr. Fantastic, Elizabeth Montgomery as The Invisible Girl, William Demarest as the Thing and Tim Considine as The Human Torch with guest appearances by Burgess Meredith as The Mole Man, Fabian as The Sub-Mariner and wrestling legend Bruno Sammartino as The Hulk.
Of all of those cast members the only one I take issue with is Demarest as The Thing just because of the actor’s advanced age. Someone like Dan Blocker would have been my casting choice.
Take a look at the site; it is a nifty little bit of creative fanboyism.