Welcome and congratulations, the Old Town canoe with serial number 175545 is a 16 foot long Otca model with narrow two and 3/4 inch planking and a keel. It was built between December, 1965 and February, 1966. The original exterior paint design was similar to the one shown at http://www.wcha.org/catalogs/old-town/designs/design04.gif which was known as their design number four. This shipped on March 4th, 1966 to Newbury, Massachusetts. 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. 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.
Benson, I can't tell you enough how much I appreciate this information. Thank you very much! I've done some strip built canoes - but this will be my first attempt at a canvas canoe restoration.
Bill, check out the books available from WCHA. Between them and this site, you will find all the information you could possibly need for your restoration!