Jerry sells some pretty workable small blades, about 4' in diameter. They're plastic.
I know of another fellow who makes fiberglass reinforced nylon blades, and hubs. They're about 8' diameter and I think the blades, with hub will be between $150 - $200 for a set of 3. He's got a neat new hub that's got 4 1/2" holes on 4" dia circle - so they are a pretty good match to Hugh Piggott's plans. I don't care for the flexibility of them.. they might be a bit loud, but they are really strong, I don't think you can break them.
I have a good freind up here who's been making wooden blades for me. A 10' set would be around $250 with baltic birch hubs. I like these a bunch - they're from laminated cedar. I'm doubtful that replicating one of them from fiberglass would be an improvement... these look neat, they're nice and light and perform really well.
So there are some options I know of. If you're interested in either of the two latter options you can send me an email about it for more detail!