Sorry I don't have the date of the catalog from which the following are taken:
“
Old Town ‘IDEAL MODEL
’ Canoe”
Here is a canoe of surpassing refinement and distinction. It is the regular Charles River Model in A. A. Grade, with open mahogany gunwales and fitted with the special feature of Half Ribs. Embodies charm of beauty in appearance and utility. The practical feature of open gunwales and half ribs, with high quality, stamp it as the canoe par excellence.
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The only differences in the specifications listed above between the Ideal and the Charles River are the weights -- the Ideal is 2 pounds heavier -- probably because of the half ribs.
In her history
The Old Town Canoe Company: Our First Hundred Years Sue Audette writes:
"It seemed that each year the company offered something new. One modification, in particular, was revolutionary: open gnwale construction. This was first seen on the 1907 Ideal Canoe, availablein the AA grade of the 16-foor and 17-foot Charles River models. Prior to its introduction, canoes were all fiished with closed gunwales, and when the boat was stored upside down, water did not drain easily, causing the gunwaless to rot. The new method finished the canoe with inner and outer gunwales, which were rabbeted to cover the top edges of the planking and canvas, leaving the tops of the ribs exposed, thereby creating drainage holes between them. This extended the life expectancy of the gunwales considerably.
"The Ideal's second new feature was half-ribs between the full ribs. This construction technique became an option on other models and eliminated the need for floorboards to protect the planking. (E.M. White had utilized this technique in the3 early 1890's.)"
pp. 46-47.
Sue also reproduced a page from the 1908 catalog:
p. 139
By 1922, when your ideal was built, open gunwales were standard on Old Town Canoes, but the half ribs were only an option except on the Ideal, where they were standard.