Very cool boats. Being an aluminum boat fan, I've always enjoyed watching the (too few) guys who built their duck boats out of aluminum. Can you give us a few more details, like have you got Coast Guard certification so we can register your boats? How about flotation, is there any? If not would you be willing to add compartments fore and aft for flotation foam? She looks light enough for reasonable rowing, have you looked at adding raised, reinforced oarlock sockets?
From the photos, which look great, one additional area I would have concerns with, is the light weight keelsons / runners. They look like they would take a wicked beating when dragging the boat off a tidal shore. Could they be doubled up with space between for a replaceable high density plastic insert? Closed channel at the stern and a few pop rivets into the plastic down each side should lock it in place while remaining easy to swap out.
Wish the boats were closer than a 9 hour round trip, as I'd love to see one. Let me know if your ever dragging one north.
Scott