Give the guy a break, he aged at least four decades on only 19 years.
When you look at the ages of the actors who played him and consider that people’s skin age faster under harsh sun, the discrepancy shrinks. If you make the Clone Wars longer (three years is too short for such an epic, galaxy spanning, Republic destroying conflict) Owen and Beru’s ages make more sense in the PT and their apparent age in Ep 4 no longer is off at all.
Granted people can look older than they are, but Ewan McGregor was around 35 when filming ROTS, and Alec Guinness was in his 70s when filming Star Wars. Sure, actors don’t always play characters that are the same age, but unless it’s obvious through makeup or exposition it’s a good metric. I could see McGregor being as old as 45 in ROTS and Guinness being as young as 65, but it strains credulity:
I also can’t help noticing that Guinness’s nose and ears are proportionally much larger than McGregor’s, and this is a characteristic not of harsh environments but of advanced old age which only gets more pronounced in Empire and Jedi.
Alec Guinness was 62 when he filmed Star Wars in 1976. Ewan was 31 when he filmed AOTC. To me it seemed that they aged him for ROTS plus I think the Clone Wars should be much longer than 3 years (this is one of the many ages that makes more sense if it was longer. And 20 years on a planet like Tatooine can make your skin age an extra 10 easily, so either way, there is an extra decade that accounts for the aged look of the 3 residents of Tatooine in question.