"He's 62 and, having a still reasonable amount of hair, I think he looks, at most, 62."
I'm 5 years older than Bill, compared to me and most of my contempories he looks 15 to 20 years older.
I would have thought by looks that he was at least mid to late 70s. One of my friends like me still has (mostly) dark brown hair, one is bald but looks younger than me the others are comparable, we all still indulge in various sports etc and none of us smoke, that is a skin ager.
I don't who the 62s are that you know but they should look after themselves a bit more.