Been a while since I've posted anything but here goes. I believe that the Old man on the barrel is Jaim Farstrider, because of a few reasons. First the age is right JF has to be about 70 (he was early '20's when Malkier fell, and that was 47 years gone now). Second, he has memory problems which coincide with the last piece of info we have about JF (the Ogier story). Now weather or not this is the same man that we see in Graendal's gateway is an entirely different theory but I see it as likely especially if it is Farstrider because we know he had dealings with Ishamael and him in the clutches of another Forsaken is likely. (Since Ishy probably used Compulsion on him. Peace favor your swords.