Well, the Carleton with this serial number is 18 feet long with long decks and lots of mahogany that shipped in 1922 which isn't likely to be yours. I found two nearly identical 16 foot Carleton canoes in the 1x703 sequence so the deciding factor may be the type of wood used in the decks, seats, and thwarts.
The Carleton canoe with serial number 15703 is a 16 foot long, CS (common sense or middle) grade, Carleton model with red western cedar planking, open spruce gunwales, maple decks, maple thwarts, maple seats, and a keel. It was built between September and November, 1920. The original exterior paint color was dark green. It was shipped on April 4th, 1921 to New York City.
The Carleton canoe with serial number 19703 is a 16 foot long, CS (common sense or middle) grade, Carleton model with red western cedar planking, open spruce gunwales, birch decks, birch thwarts, birch seats, and a keel. It was built between April and July, 1927. The original exterior paint color was bright red. It was shipped on July 22nd, 1927 to Hopewell Junction, New York.
Scans showing these build records can be found by following the link at the attached thumbnail images below. These scans and several hundred thousand others were created with substantial grants from the Wooden Canoe Heritage Association (WCHA) and others as you probably know well. 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 will join or renew your membership to the WCHA so that services like this can continue. See
http://www.wcha.org/about-the-wcha/ to learn more about the WCHA and
http://store.wcha.org/WCHA-New-Membership.html to join.
It is also possible that you could have another number or manufacturer if none of these descriptions match the canoe. Does it have diamond headed bolts and do they look original? Is there any evidence of the original paint color? Can you attach some pictures? Feel free to reply here if you have any other questions. Thanks,
Benson