Randy,
I ran a quick check on Old Town and Carleton with the following results.
OT #18956 17 was built as a 16' Charles River, shipped on 4/16/1912 to Nebraska and painted yale blue. This same serial number in Carleton was an 18' model.
OT 18746 was built as a 16' and shipped to NY on 8/21/1911. Carleton #18746 is the best match with what you provided. This 17' model built in CS (common sense) grade was shipped on 12/28/1925 to Florida with spruce gunwales and birch decks, seats & thwarts.
Why you have two serial numbers is a puzzle to me and maybe others can help with that. If you can post some pictures, the experts here can be very helpful. If you have not already done so, pleae consider joining the WCHA to help support this research service and other services which have been brought about by grants and volunteer man hours. This is also the best site for repairs and restoration of this type of craft. Build records are attached.
Regards,
Ric Altfather