I think the seat locations were changed a bit sometime after 1914 -- perhaps when OT went to open gunwales -- although it might be that the rib width and placement is what was changed..
Here are pictures, bow and stern seats, of our 1931 50 Pound OT at the time I bought it in 2009 -- the original cane is missing, but the seats appear to be in their original position. I am not sure that the seat hangers are original. The bolt holes in the gunwales indicate that theplacement is original.
Here are pictures of another 15’ 50 Pound OT, from 1934. The seat placement seems the same as the 1931, and note the lack of seat hangers except on the rear rail of the stern seat.
stern
bow (with other pictures, it is clear that there are 12 ribs between the front rail and the rear edge of the front deck on this canor)
Counting ribs can give guidance for seat location, but not certainty. In the 1931 canoe, I count 13 ribs between the bow seat front rail and the deck; in the 1934 canoe, I count only 12 ribs, notwithstanding that the deck of the 1934 canoe seems a bit shorter than the deck of the 1931 canoe. And on Benson's 1914 canoe, both seats seem closer to the ends of the canoe.
Here are pictures from the 1937 and the 1958 catalogs -- the seats seem to be similarly located to each other and to the canoes above, but note the hangers shown in the later catalog.
As with many elements of boat design, canoe seat placement presents conflicting interets -- having the weight of the paddlers closer to the (wide) center of the canoe tends to give more stability, while having the paddlers closer to the (narrow) ends of the canoe generally makes for easier and more effcient paddling.
Could it be that the bow seat was moved aft a bit in the 1930s and later boats to facilitate solo paddling with the paddler sitting "backwards" in the bow seat?