The Old Town canoe with serial number 171171 is an 18 foot long Otca model with a keel and sponsons. It was built between June and August, 1961. The original exterior paint color was dark green. It shipped on May 15th, 1962 to Trude, Idaho. A scan of this build record can be found below.
This scan and several hundred thousand more 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/catalogs/old-town/records/ if you want more details. I hope that you will donate, join, or renew your membership to the WCHA so that services like this can continue. See https://www.woodencanoe.org/about to learn more about the WCHA and https://www.woodencanoe.org/shop to donate or join.
It is also possible that you could have another number or manufacturer if this description doesn't match the canoe. Feel free to reply here if you have any other questions,