The first question is how are you planning to shorten the design? Take a couple of inches out of each station spacing? Cut two feet out of the middle? Are the stations at the same points for both the bottom and side panels?

Resizing a S&G can be tricky because the panel shapes are based on flat panels while the panels are curved as installed in the boat.

My biggest concern is not whether you can make it go together (with a little fiddling I'm sure you can), but will you lose stability. As I remember the North Bay is fairly narrow. As you shorten the kayak you lose displacement that contributes to stability. This is especially true if you take the extra length out of the middle.

I'd like to hear some dialog on this topic, it's an interesting one.