The Old Town canoe with serial number 181203 is a 13 foot long lightweight model with a keel, rub rail, and stem band along the full length of the keel. It was built between July, 1968 and October, 1969. The original exterior paint color was red and it was later painted orange. It shipped on October 8th, 1969 to Wheeling, Illinois. A scan of this build record can be found by following the link behind the thumbnail image attached below.
This scan and several hundred thousand more 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/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 this description doesn't match your canoe. The Trapper model was built on the same form but the exterior was covered in fiberglass instead of canvas. Feel free to reply here if you have any other questions,