Old and rare models of canoes, like old and rare models of any product, are often rare for one good reason: They were never popular to begin with; there never was much demand for them. Hence, demand for such an unpopular old model will even be less now than when is was new. Such old models won't sell for much much more than a minimal "something that floats and can be paddled/motored" value.
Of course, there are rare buyers who are interested in collecting rare models of rare old things. If a seller can luck into such a buyer, a higher price can be gotten. The best tactic is to offer the canoe for sale in all available venues, such as the Classifieds forum here and other boating websites, and various Facebook pages such as Marketplace, as well as local venues such as Craigslist.