I agree, that doesn't look like a factory made transom. The Old Town canoe with serial number 116715 is an 18 foot long, GS (guide special or utility) grade Guide model with red Western cedar planking, open spruce gunwales, oak decks, oak thwarts, oak seats, and a keel. It was built between December, 1935 and May, 1936. The original exterior paint color was G. S. (Guide's special) bright red. It shipped to Duluth, Minnesota on June 6th, 1936. A scan showing this build record can be found below.
This scan and several hundred thousand others were created with substantial grants from the Wooden Canoe Heritage Association (WCHA) and others as you probably know well. 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.
Benson