Have a look at the website for Pocock rowing. They've been making shells for a loooonnng time. (They built the men's 8 for the USA Gold medal team in 1936!) Sliding seats and part galore, but no plans I'm afraid. But if you've got a real passion to have one, they offer a hand built cedar model for a mere $6000.+!! They've got a stash of old growth cedar,logged earlier this century, that is so fine grained you wouldn't belive it. I've seen several close up and they are as fine a work of art as some of the kayaks I've seen here on this board and at the R2K.

Enjoy!