He's doing one hell of a good job for a 16 year-old! I think my dad started at either 14 or 16, he met mom a few years later and she sort of ruined everything by distracting him, lol.
I just love how a photo can change everything: He doesn't look 16 at all here, but you can tell his youth much better in the other images. Particularly in "absolute category" done for show: where he lacks the "filled in" quality the other men have. Very interesting to see that difference Would be cool to see the comparison if he keeps it all up, and you're there to take a photo of him when he's a grown man.