I asked the seller for the serial number because I was curious to see what the build record says. The seller gave me two numbers, neither of which appears to be for that canoe. Both numbers he found were followed by a "17", so I feel it may be a 17 foot canoe. One serial number was for a 16 foot boat (not a canoe) and the other was for a 17 foot AA grade Otca, no mention of sponsons or a motor, dating from 1916.
The canoe in the picture appears to me to be a CS grade (thwart looks like ash) HW with sponsons. I see diamond head bolts there too... although they could have been added during a restoration. I explained this stuff to the seller and asked him to check the numbers again, at both stems, and maybe he'll get back to me.
It may help if others poke at him too, because he's maybe figured out I'm only curious and don't have that kind of money.
Asked the seller to check the serial number at each end, and he provided two possibilities-- one of which he'd given me before. He says it's either 33739-17, which is a 16 foot boat (not a canoe)... or 38739-17, which is a 17 foot AA grade Otca (no mention of sponsons or Evinrude). I poked around the serial numbers, trying different combinations, and didn't find anything close--- 33789 is a 17 foot Charles river; 38789 is an Otca... nothing a fer-sure match.
Thought maybe some of the others here who have the s/n CDs would like to play this numbers-game too. Meanwhile, I'll ask the seller if he'd like to take a picture of the serial number, and explain that hundreds of pairs of eyes can often see things one pair cannot.
Checking again, the seller says one end is too faint to read except for the length (17). The first three digits at the other end appear to him to be 397 and the last two are 33, 39, 38, 88, or 99. He says all the threes, eights, and nines look similar. I checked 397 with all those possibilities-- none had sponsons... 3 are 17 footers-- one is an Otca and two are Charles Rivers. The canoes date from 1916. The seller says the engine is dated 1918. I'm also looking at the buyer, in case it's someone connected with a business that might have modified the canoe.