I gotta agree! He's quite the handsome dude!
I think dogs typically have attained their full height by 8 mos on average, but still put on body mass till they're about 12 mos of age--and that held pretty true for our guys. By 6 mos, though, their growth spurts seemed to slow down. They topped out at about 60 lbs, so not quite as big as your boy is going to be!
Still, I'm thinking if he's 60 now, he may top out at 80 or 85. Maybe?
I don't know for sure, but I still know he's a handsome dude!
It'll be interesting to see how big he gets. I've heard that the larger breeds grow more slowly, so if the Great Pyr comes out in him, he could well get bigger! He doesn't seem to have the massive bones of a Pyr, though.