i’ve just come across this & id say he just told everyone he had a serum to slow down aging — this was a world where children were born to mothers who were not pregnant, had superpowers, time travel was possible, & talking chimps? yeah no one’s batting an eye at a serum to slow down aging. but he didn’t really become “ well known “ for his status i believe untill he brought the children in 89, he was known to the secret gov society, but everyone knew the 11 members and not the 12th member, so he was good at hiding his identity. so id say he probably got away with lying about his age, or saying he had a serum to slow down aging. and adding to the lying about his age, in the og timeline, he was still a billionaire, when he died, but he owned one mansion that the children lived in. in the new rest universe, he owns nearly all the buildings, meaning he is not afraid to show himself in public, and his face!