Your surviving deck decal might offer a clue as to the age range and possible the model class.
For most of the timeline of the company, the deck decal had three lines of smaller black text under the "Chestnut Canoe Co. Ltd." script that read
FREDERICTON, N.B.
CANADA
PAT. 1905
Here's a sample on a confirmed boat from 1970...
It was around this time that the company stopped using die cut decals that were cut around the pattern of the leafy logo and switched to cheaper square vinyl decals similar to the one on your boat.
However,
Chestnut's 1973 catalogue featured a slightly altered logo with just two lines of black text where the "CANADA" and "PAT. 1905" were now merged. You can faintly see this on the catalogue cover and a few pages within.
Here's a blurry closeup but the best image I could source. Two lines of black text are visible instead of three...
In 1974 the factory moved from Fredericton to Oromocto and produced a new decal with different font colours so that label has a distinct difference that can be easily seen. From one of your images, you can see your decal has mentions Fredericton and has two lines of black text. That would put the date roughly between 1973-1974.
As for model, Chestnut Cruisers were all built with a more narrow deck than other models in the Pleasure and Prospector classes but the deck decals was the same size for all models. On a Cruiser's narrower decks, the leafy parts often stretched out over onto the inwales.
Here is an example on a similar era Pleasure model (14' Playmate)...
And one on another early 70s Cruiser where you can see the leafy parts of the decal extending past the deck onto the inwales....
Given that your boat is 17' from the 70s, it is likely you have a Cronje model.