Yes, but I think it's fair to surmise that the human lead actors were at least portraying at least within 5 years of their actual ages. Hamill was around 24 portraying 19. If they had wanted Guinness to be even older they would have kept his toupee off. Baldness generally makes you look older. Truth is, writers didn't know how long it had been since The Clone Wars. It was left open. As much as you seeth with burning hatred towards the prequels, there is nothing to disprove their timeline in the context of the original films.