. . .
: Two weeks ago I removed the strongback and forms and glassed the
: inside of the hull with a nifty orange and black carbon Kevlar
: fiber cloth (ebay id 120708217998). The Kevlar stiffened and
: strengthened that hull like a rock! Though I had to ask myself,
: did it look narrower, or was that a trick of the eye?

: Well, 3-days ago I laid the deck on top of the hull for the first
: time and found … the deck was significantly wider than the
: hull – by as much as 1.3” at the cockpit! Welcome to my
: nightmare!
. . .

Have a look at http://www.kayakforum.com/cgi-bin/Building/index.cgi/page/1/md/read/id/204873/sbj/spreader-sticks/ - did you use spreader sticks to stabilize the hull and deck?