Welcome, the Old Town canoe with serial number 175467 is an 18 foot long, Guide model that was built on the Otca form with two and 3/4 inch wide planking, mahogany decks, a keel, and the stern seat moved two inches forward of the usual position. It was built between December, 1965 and January, 1966. The exterior paint color was G. S. (Guide's Special) green. It shipped on April 19th, 1966 to Toledo, Ohio. A scan showing this build record can be found by following the link at the attached thumbnail image 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 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.
My guess is that Guide's special green was slightly lighter than the more common dark green but there is no easy way to confirm this assumption. This color was never shown on any of the known paint cards. It was a reasonably common color during this period. The factory typically used high gloss exterior paints and varnishes but restorations of very old canoes often have less gloss which seems more in character for the age of these boats. See
http://www.wcha.org/forums/index.php?threads/14963/ for another example of a canoe like yours.
The page at
http://www.wcha.org/content/old-town-canoe-company has some more details about the Guide and Otca models. The differences between two models below the waterline are very subtle as the cross sections shown in a 1920s catalog at
http://www.wcha.org/catalogs/old-town/hull-x-s.gif indicate. It was not unusual to have a Guide style canoe with low ends built on the Otca or other forms. Feel free to reply here if you have any other questions.
Benson