The Stowe Canoe Company went out of business in 1991. They never made a Kevlar canoe or one that long. Their canoes were fiberglass with thin mahogany ribs and wood stems and keel. They were called Mansfield canoes.
The Adirondack Canoe Company is still going strong and is located in Minerva, NY. You can contact them for more information. However, they were founded in 2013.
There is a St. Regis Canoe Outfitterslocated in the town of Saranac Lake and on Floodwood Pond that has been in operation for 37 years, but the don’t manufacture canoes.
Slipstream Watercraft produces two unique designs from the historic shop of Bart Hauthaway (1924-2002) – the Woods Canoe and the St Regis. Both are of John Henry Rushton orgin/inspiration. Slipstream has obtained use of the original Hauthaway molds from Bob Wolfertz who, at times, worked hand and hand with Bart. Right timeframe and in Kevlar, but only 12’ long
It appears you have a real mystery.