That was an early guide before everything was locked down and before more movies being made. Nothing in the movies mentioned exact ages by that point. Alec Guinness turned 62 while filming in 1976. And I don’t really agree he was made to look old, other than the fact he grew a beard. His hair was already gray/white and in interviews from 1976 out of costume he was balding and looked as old, or older. Ewan McGregor today is just ten years younger than Alec was when he filmed it in 1976.