Robertson was building canoes in the Charles River area in the 1880s, and was building canvas canoes certainly by 1895. Robertson and many of the other CR builders (Arnold, Kingsbury, Crandell, e.g.) built canoes, basically in the same form, right into the 1940s.
With spectacularly figured decks like yours, I'd be inclined to try to save them if possible. If you can pull the cracks closed while the decks are on the canoe, you may be able to glue them back together with epoxy. Some dutchmen applied from the backside might also be helpful. If the cracks are due to shrinkage, you may not be able to pull them together. In that case, gluing in thin splines followed by dying the splines to match may be an option. Those short cracks near the coaming in your photo I probably wouldn't even bother with. Judging from the repairs at the tips, I expect you'll also have to scarf in new tips.
I would consider replacement with new wood a last resort. And, if this option is excercised, look long and hard for good figured wood to use.