Welcome, the Old Town canoe with serial number 205989 is a 10.5 foot long fiberglass Rushton model that originally weighed 21 pounds. It was built between January and February, 1975. The original exterior gelcoat color was avacado. It shipped on March 10th, 1975 to York, Pennsylvania. The back side of the card indicates that there was some aligation on the righthand side of the stern. Scans showing both sides of this build record can be found 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 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 renew.
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.