Hi Dick--
It seems both serial numbers turn up canoes that were 16 footers with closed gunwales, shipped to Canada... the main difference would be canoe model, wood species of the deck, and presence of a keel.
OT 20662 is a 16 foot CS (common sense, or middle) grade Charles River model canoe completed January-- March of 1912. It has Western red cedar planking, closed spruce gunwales, birch decks and ash thwarts and seat frames, and a keel. It was originally light green and was shipped to [someplace in] Canada on April 15, 1912.
OT 20362 is a 16 foot CS grade MC model canoe that was completed January-- March of 1912. It has Western red cedar planking, closed spruce gunwales, and ash decks, thwarts, and seat frames. No keel mentioned. Original color was dark green and it was shipped to Montreal on March 19, 1912.
I believe the MC is one of those models, like the XX and original Molitor, that never appeared in a catalog. The scans of these record are attached below-- click to get a larger image.
This scan and several hundred thousand others were created with substantial grants from the Wooden Canoe Heritage Association (WCHA) and others. A description of the project to preserve these records is available at
http://www.wcha.org/ot_records/ if you want more details. I hope that you and anyone else reading this will join or renew membership in the WCHA so that services like this can continue. See
http://www.wcha.org/wcha/ to learn more about the WCHA and
http://www.wcha.org/join.php to renew.
It is also possible that you could have another number or manufacturer if this description doesn't match your canoe. Feel free to reply here if you have any other questions.
Kathy