Hello-- Old Town 141335 is an 18 foot, unstated, but probably CS (common sense or middle) grade guide model canoe compled December 1944 to February 1945 with open spruce gunwales, ash decks/thwarts/seats, and a keel. It was painted dark green with a guide special green bottom and shipped to Portland, ME, on March 5, 1945. As a war-era canoe, it may have slat seats and other aspects of the canoes built when there were shortages in materials. You may find more information on war era canoes by using the search function on the upper right. It's wonderful to have a family heirloom canoe! Image of the scan of this record is attached below-- click on it 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.