[x_Gamblor_x]

My guess is that lefty limped with 77, 55, 22 or 6c8c. Ac9c is out for me because of his raise on the turn together with your "straightforward not strong" read. I lean to 68c because that gives him more incentive (13 outs to a strong hand) to call the flop cold. That would explain him raising the turn with a made staight. I would have to ask myself if he's the type of player who'd limp with a hand like that from ep - or would he only limp with a small pair?

I also guess that your lp preflop raiser has a decent overpair that he is hoping will hold up. I don't put him on a flush draw because of his calling down on the river.