See picture below.

I wrote a reply in my usual length and it got eaten as I tried sending it, so rather than remember what i wrote I'm just sending a picture. This tool costs $59.99 from Sears. You could build something similar rather easily.

More information from Sears. www.craftsman.com

Look for routers and router tables and accessories.

This one is almost a 2-d router, but it can do some relief work. A true 3-D router would have some sort of spring or counterbalance supporting the router so it could go up and down over a distance of maybe 4 to 8 inches. This one might have enough working range ( depthwise) to copy your paddle.

It should certainly be usefull for copying the spoon shape of a paddle blade. Roughing out blades in this manner would be a fast way to get them even. Final shaping with sandpaper should complete things.

Sear had another router gadget that resembled a cross between a lathe and a router. Your original table leg, post, gunstock, or other odd shaped item sat below the router, which slid along a pair of rails. the piece you were cutting could rotate 360 degrees, and so could your original part, so the router could cut all sides. I haven't seen one of those in a few years.

Hope this helps.

PGJ