Early results were very good, 1.7v soon after light up. I think the thin steel plate heated up faster, I also got a better coating of heat sink compound on the peltier and on the heat sink.
Unfortunately as the rig got thoroughly heated up voltage dropped to .5, my little heat sink can't shed heat fast enough to keep up with the lantern.
I tried stacking a heat sink on top of the existing heat sink which seemed like it was working at first but in the end just added thermal mass, once the add on heat sink was heat soaked it dropped back to the same .5v I was seeing with just one heat sink.
So I've managed to get the hot side plenty hot, I've got a USB booster that will take anything over .9v and boost it to charge a USB device, the 1.7v I had when I first lit the lantern is plenty, I'll probably need more current but I can get that with a couple peltiers in parallel. What I need now is to keep the cold side temp such that the voltage stays up.
More experiments to come!