After a season of use I thought I would update this thread with some lessons learned
1) the cockpit coamings, fortunately I never showed the quick installation catch I devised, it turned out to quick release at times of it's own choosing, I reverted to the cursed thumb screws as shown on the plans, this adds nearly 10 minutes to the assembly time.
2) The stringers all snap together in the middle of the boat, unfortunately the stern ones have an aluminum hinge really close to the frame this limits the amount of flex, this has been no problem for the smaller stringers but too much for the larger 3/4" gunwale stringers about a month apart they both split, fortunately a 10 minute repair with a hose clamp in the field. I have since gone from a snap joint to a bolt and wingnut that has reduced the required flex from 18" to 6" and the have been no further problems.
3) The fabric for the hull turned out better than expected
http://www.outdoorfabricscanada.com/Sam ... _3430.html
True I didn't have high expectations but it has survived being dragged up gravel beaches, landing on rocky beaches with caution, and a lot of worn stone beaches it has a few scuffs except for one incident
On one of the first few trips out I succeeded in running on to a rough granite boulder at 5kph we scrapped along one stringer and finally came to a quick stop in about 8' stuck on the rock. The 1/2" cut in the fabric below is the result

As the fabric is tight across the stringer no significant water came in and we didn't know about it until an hour later when we were putting the kayak on the car and a couple of cups of water ran out. I've since put 3" strips of cloth over all the stringers below the waterline and had no further problems, if I was doing it again I would double all cloth below the waterline to form a double bottom and that add wear strips to the stringer, I think that would be fairly idiot proof a prime requirement for my boats.