55 25NL
Flop and turn seem standard.
River is worst card in the deck. However I don't think he has a tonne of 7s in his range after I x raise the turn. But I think all his nutted draws still call and over pairs.
I think we have to call his bet on the river because: 1. He could be bluffing missed draws. 2. He could be betting a 3 or overvaluing an over pair.
If I had known that villain is capable of playing 67o that way then I think we can fold.