You are correct. It is not necessarily simple to take an existing design and build it as a stitch and glue kayak.

The first question to ask is, "Is the design developable?" Plywood will bend easily in one direction. And it will bend almost as easily in the other direction. But it will not bend in both directions at once. A design is said to be "developable" if the plywood panels can be bent to the proper shape in a series of one directional bends. Computer modeling can help here. So can building a scale model.

The second question is, "What shape are the panels when they are laid out flat?" It may be possible to make cardboard patterns from the original boat. Something to consider is that the panels can go together and produce many different hull shapes. It would be a good idea to make cross section forms at a few key points to help maintain the proper shape.

Mike Scarborough
Friendship Kayak