Old Town Canoes typically have a 5- or 6-digit serial number, so look to see if there might be a digit or two in front of the 8. Look on both stems; sometimes the numbers are clearer on one end than the other. Also look for two digits that are separated from the main set of digits, which should correlate to the length of the canoe, i.e., "17" would be found on a 17 foot canoe.
Pictures will help identify the canoe. Decks, stem profiles, seats, thwarts, ribs... We like pictures of canoes!