In another thread, Benson says: "My next research project is to determine when Old Town switched from using straight ribs to tapered ones. This appears to be between 1914 and 1919 but I am still narrowing this down. Does anyone have a canoe in this range who can send some pictures and the serial number (at the risk of thread drift)? It is also interesting to note that the Indian Old Town canoe shown at http://forums.wcha.org/attachment.ph...0&d=1383597034 and described at http://forums.wcha.org/showthread.php?11487 has tapered ribs. This change may be another suggestion that came from J. R. Robertson. Another mystery," My OT HW #52727 has tapered ribs. The build started in November 1918, so this seems to be consistent with the theory... Let me know if you want dimensions.