The Old Town canoe with serial number 121761 is a 16 foot long, CS grade, HW (Heavy Water) model with red Western cedar planking, open spruce gunwales, oak decks, a keel, and sponsons. It was built between May and July, 1937. The original exterior paint color was dark green. It shipped on July 6th, 1937 to Pittsburgh, Penna. A scan of this build record can be found by following the link at the attached thumbnail image below.
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. Congratulations on your purchase.