Getting close to finishing a Yost SeaTour EXP 15 for myself.
To fit my physique (fully developed - I hope) I have put in a larger cockpit, moved the #3 frame fwd 4 inches to match, added a partial frame between #3 and #4.
The cockpit frame is coutoured (just because I like the shape).
Again trying the Morris style splined skin installation. Next week should see it coated. Just a little too late for the Sail Oklahoma messabout.