171957 is an 18' square end paddling canoe finished April-June of 1962. It has half-ribs, a keel, outside stems, sponsons, rub rails and a rowing seat and originally had design #45. Shipped 5-17-63 to Woodland, ME. A copy of the scan is 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 will join or renew your membership to 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 join.
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.