Yea I thought this was the man from talahasee. Which means he must have appeared in the box sometime before, perhaps when the plane crashed?

I definitely think they'll make Cooper the real Sawyer, I think somehow he'll see Sawyer referred to as James Ford and think nothing of it, then Kate will call him Sawyer or something and Cooper will be like "That's weird, I used to be called that" or something innocent and JamesSawyerFord will make the connection.