The three Old Town canoes in my garage from 1907, 1931, and 1936 all have hand caned bow seats that are nearly identical so your fifty pound model may have been similar. Each was made from one and three quarter by seven eighths inch stock and the bow seat has an outside dimension of fifteen by ten inches. The inside dimensions are eleven and a half by six and a half inches. There are fifteen by eight holes spaced three quarters of an inch on center and three eights of an inch back from the inside edge with no holes on the corners as shown below.
I suspect that the seats were all made the same since the size of the people using the fifty pound models were not substantially different from the other models. Hopefully someone who owns one can reply here and confirm that for us.
You may have noticed I recently posted a serial no. request for a 50 pounder. I don't think it will help you though. It is later 1960 vintage and has a mast seat, that was added later and includes machine made/pressed cane.
Fitz: Thank you, a sail rig was added to this 50 pounder and appears to have been sailed hard (numerous cracks in the inwales etc.) As much as I love to sail, I'm not going to put the sail rig back on, I'll save it for something down the road. I think the construction of the 50 pounder is light for enduring the forces of a sail rig.