Welcome and congratulations, the Old Town canoe with serial number 226596 is a 16 foot long fiberglass Laker model that weighed 74 pounds. It was built between May and June, 1979. The original exterior gelcoat color was green. It shipped on June 12th, 1979 to Milford, New Hampshire. The back side of the record indicates that there were some small pock marks in the gelcoat on the ends that looked like buckshot so it was sold at a discount. 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 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.
I am not an expert on fiberglass but my guess is that small pock marks in the exterior gelcoat would probably be the result of using a spray gun that wasn't throughly clean and dry. The result is a canoe with parts of the outside that look like it has been hit with buckshot.