Just to illustrate, here's the lineup for 1965. It shows the 100 series with US Valiant bodies and the Signet and 200 series with US Dart bodies (with Dart front clips):

For contrast, here's the 1964 lineup, showing Dart bodies with Valiant clips:

And 1966, with only Dart bodes:

I have no idea why they changed it around so much during the 4 model years of 1963 to 1965, but suffice it to say that things were probably tumultuous in the Canadian auto industry around the 1965 Canada-US Auto Pact.

Sorry to go on about it... I've always been fascinated by the differences between Canadian and US cars, and having been a '65 Valiant owner myself, I felt compelled to research the differences a little. Hopefully the info will help your project along as well!

If you want to see the rest of the brochure pages I posted above, they are at the link I posted below: