Although many see Kirby more as his character the Thing -- a wisecracking, cigar-chompin' brawler with a heart of gold -- I suspect there may also be a lot of Jack in Mister Fantastic, a brilliant inventor and designer with a keen intellect. The image of Mister Fantastic on the cover of Fantastic Four # 7 (1962) looks like Kirby to me, but that wouldn't be the first time an artist used themselves as a model.
Most Kirby scholars agree George Roussos inked this cover, but some suspect it may have been a rare example where Kirby inked his own 1960s Marvel work.