I agree with you that after villain raises that flop, 66 or 77 is definitely a large chunk of his range. I would exclude AA because he should be 3-betting that pre. It appears that his raise on the flop would be to stop you from chasing straights or flushes, which are a huge part of your range when you open in CO.

HOWEVER, his large bets (approx. pot size) on both the turn and the river are extremely strange if he has a set. Particularly on the river, why is he betting so large when the Qh is basically a brick on that board? He should be betting smaller to induce a call from you, especially if he puts you on Ax.

I'd personally call because his story on later streets hints to busted flush / straight draws. There are so many combos of these, yet there are actually only 6 combos of 66 and 77 that villain could have.

Thoughts? Agree? Disagree?

Villain isn't full stacked so we do have a little info, probably a casual.
Versus that there's a good chance I come over the top on the turn, but even if I call I'm never folding the river with top two versus a casual, they could just have anything, couldn't rule out any Ax or any two pair even, can we.

As played and after improving on turn I'd just call it off I think and move on.

i would play the set here sameway , cause K and Q are better cards for your range so you should be rather strong ,plus the potsize bet is just great vs regs.
btw. ive played him but cant remember exactly if it was rec or regfish.