The Morris book has several skin boat designs, it's years since I read a friend's copy but as I recall they are adapted from aboriginal boats, mostly kayaks aof various specialized types, and an umiak or two. Platt Monfort's so-called Geodesic Airolite designs are another source.

Morris's and Platt's designs seem a bit over-engineered to my eyes but I haven't built SOF yet; they seem to built all the strength and stiffness into the frame and make no allowance for the contribution of the skin, which should be considerable; they seem no lighter than my plywood canoes.

There are more SOF kayak designs than canoes, but plenty of canoe designs for other construction methods. The Platt and Montford designs are good guides for how to arrange the stringers, seats and floors, which are different compared to other construction methods.

Some more links -
http://www.instructables.com/id/Build-a-Greenland-Kayak/
http://www.jonsbushcraft.com/sof-skin-on-frame-canoe-3.htm
http://www.gaboats.com/boats/ (not free but reasonably priced)
http://watercraft.clearstreamwood.com/products/kayaks/skin-on-frames/ (the designs here look remarkably like those in Morris's book!)

I recently built an ultra-light stripper canoe at http://theancientkayaker.weebly.com/canoes-rose-lee.html

- it had an unusual construction, no glass, laminated half-ribs provided the cross-grain strength, and the bottom football-shaped panel was marine plywood. At one time I hoped to do a SOF version by skinning a similar frame (visible in the blog) with the ply bottom forming the floor. I was planning to beef up the gunnels, attach the ribs to the underside of the bottom panel and add a keel as well as the necessary stringers. Don't know if anyone has built a SOF that way before . . .