Hey, that sure looks like a lot of fun! I found that Popular Science issue on Google books. I had to back up a bit from the article on page 127 to see the plans. I think that was a good modification you made using a steering wheel instead of steering with your feet.
Reminds me; in 1972 when the Ashtabula was returning from a 10 month Westpac cruise I drew a cartoon (not very big or very good) of the AO-51 up on hyrdofoils and headed home.