We ( means me) have made hundreds of such paddles, working with a genuine one sent in from Hong Kong and the measurements page.
Recently the last of the original Old Mutual sponsered paddles have been spruced up and sold at a good price.
Supplier of Wooden Kit Boats,CNC design,epoxies,bronze nails,Beech,Ash,Teak,marine and exterior grade plywood,bending plywoods and Flexible veneer sheets. Agents for these and many other companies: North Sails,Harken,Lewmar,Ronstan,Raymarine,Yanmar,International Paints. See also our blog on cars,its another side of what we can do,try this link http://royckdboats.blogspot.com/