Hi Andy,
Old Town 134435 is an 18 foot CS (common sense or middle) grade guide model canoe that was completed December 1941 to April 1942. It came off the form ten days after the "date which shall live in infamy". A cool thing about owning an old canoe involves consideration of the historical perspective, IMHO.
Anyway-- the canoe has open spruce gunwales, ash decks/thwarts/seat frames, a keel and was originally bright red. It was shipped to Camp Winnemont in West Ossipee, NH, on May 12, 1942. Image of the scan of this record is attached below-- click on it to get a larger image.
This scan and several hundred thousand others 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/ot_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/wcha/ to learn more about the WCHA and
http://www.wcha.org/join.php to join.
It is also possible that you could have another number or manufacturer if this description doesn't match your canoe. Feel free to reply here if you have any other questions.
I believe the serial number on a Robertson is found on the stem. Because there are no records for the company, the serial number may not say much... but you might want to use the "search" function (above and to the right) to find older posts about Robertsons that could help you understand what you have. There may be information in back issues of Wooden Canoe.