The full answer sems to be running afoul of the spam filter, so I'll post it in sections -- while I try to see what awful word I've used.

: I picked up another book on Amazon, to confuse myself further. It has the
: plans for the Walrus Esquimo Kayak that was created by Norman L. Skene,
: published in 1923 in The Rudder magazine. Apparently it was westernized re
: construction from an actual native kayak.

The "Rudder" article is reprinted in the back of Putz's book. Skene copied the measurements from a native craft he saw. On page 2 of Putz's book is another drawing based on Skene's measurements of this boat, which was published in Adney and Chappelle's "Skin Boats and Bark Boats of North America", which I believe is still in print and available thru the Smithsonian. The small print in the illustration says the original kayak was in the Peabody Museum of Salem, Mass, and the info for it gathered by Skene. This contradicts Putz's statement on page 1 that Chappelle took the measurements and Skeene, a naval architect, drew from them.

Either way, Putz and his artist, Spencer Lincoln, cleaned up the design a bit and redid the 17 foot boat. Then they incre ased the boat dimensions, by 18 percent, which Putz calculated would give about a 21 foot boat. Instead of actually making the boat 21-feet long, though, he re-spaced the building forms, putting them closer together, so that he ended up with an 18 1/2 foot boat. I suppose you could re-space those same forms and end up with a 21-foot boat. With such changes, you'd have three or four very different boats from the same designs.