Morris is very much into re-creation of traditional boats. Retreaval and recovery kayaks are special purpose boats and I doubt Morris was suggesting they had any general value for recreational paddling. These boats are small specific purpose creations that were used in small venues where portability and manueverabilty were paramount. And hey were sized to fit Native people who were tiny in comparison to us.
If you go into the catalog of a broadbased canoe builder like J. Henry Rushton you'll see he only went below 12 feet on specific request. These boats were prized because they were exceedingly light but never became popular as general purpose boats. Rushton had the advantage of being able to produce any hull shape that was required to get around the inevitable tippiness.
As paddle boats get smaller their payloads go down drastically and they can get very tippy if you don't design carefully. So, there is more to it than building to a set of reduced dimensions. And, even if they are not overly tippy you always have to sit on the bottom kayak style which is not everyone's cup of tea.
In Duckwork's Magazine there is a 4 part series by a guy who built a 7½' canoe. To me it looks to be of very high quality but, a complete waste of time. A paddler would have to be a wirewalker to enjoy it.

: hey all,
: This winter I would like to try making a concept again. I would like to make
: a small craft that is stable, tracks and has enough speed not be
: frustratingly slow. Very easy to store and very lightweight. Something
: that can be put into any body of water. My current thought is something
: between 10 and 12 ft (smaller is better) and open cockpit like a covered
: canoe. Basically a retreval kayak (ala Morris) but in a covered canoe
: form. So my questions: Has anyone tried such a thing (SOF or otherwise)?
: What dimensins would work best? I would love to keep it as short as possible
: but am willing to go up to 12 for more performance. Has anyone built
: something in the 10-12 ft range that can comment on how much of a
: difference there is between 10 and 12 ft?
: The width. I'm thinking between 26 and 29 inches. If Morris can get away with
: 24 inches, is there any reason that 26 or 27 would not work?
: Thanks,
: scott