I think you played it about as well as you could have. I like raising the flop as your most likely ahead unless someone holds KJ or 8J, a set is unlikely as anyone with 99, 1010, or QQ most likely would have raised before the flop. The CO may be raising on a flush or straight draw. I like the check call on the turn and river because you don't want to raise in case he 3 bets a made hand, but if he is willing to bet this hand for you then by all means let him. I would have played it the same.