Having seen it in person, I think it is war era. Steel slotted screws. But may be a replacement. It just looks not that old. The current remaining deck is a replacement triangle. The ribs are very narrow and far apart. In talking to another member smarter than me, it was suggested it may be a narrow rib New York Thompson. I think the short inwales are from rot, possibly. I wish I had paid more attention to the plank pattern. the seats are on cleats, but not quite Shell Lake type cleats that I've seen. So, I wonder if the ser no. is consistent with St Louis?