Most people here are looking for information about wooden canoes so my guess is that you have the one with serial number 166680. This is an 18 foot long, CS (Common Sense or middle) grade, guide model with a keel. It was built between October, 1957 and February, 1958. The original exterior paint color was G. S. (Guide's Special) green. It shipped on February 11th, 1958 to Seattle, Washington.
The one with number 186680 is a 16 foot long fiberglass Ojibway model. It was built in May, 1971. The decks were yellow and the hull was desert white. It weighed 61 pounds and shipped to Seekonk, Mass. on May 27th, 1971.
Scans showing both of these build records can be found by following the links at the attached thumbnail images below.
These scans 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 join or renew your membership to the WCHA so that services like this can continue. See
http://www.wcha.org/about-wcha to learn more about the WCHA and
http://www.wcha.org/store/membership to join.
It is also possible that you could have another number or manufacturer if these descriptions don't match your canoe. Feel free to reply here if you have any other questions.
Benson