Welcome and congratulations, the Old Town with serial number 180170 is a 15 foot long Trapper model with a keel. It was built in between February and April, 1968. The original fiberglass exterior was L. C. Yellow. It shipped on May 22nd, 1968 to Ogdensburg, New York. A scan showing this build record is attached 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. The information at the link below has a good summary about how to value a canoe like this and the classifieds at
https://www.woodencanoe.org/classifieds have some similar ones for comparison. Canoes with a family connection are always extra special. Feel free to reply here if you have any other questions.
Benson