Rolf
A little different direction... but I had a thread going on over at Sailing Anarchy that may overlap a little on the home building aspect.
http://forums.sailinganarchy.com/index.php?showtopic=129899
I was doing a brain storm session with the guys over there about home building curved dagger boards, there might be some golden nuggets that you could use on straight boards as well...or at least construction techniques....I put the same question here and only got one response...but I am going on 87 posts over there. Maybe something to comb thru if you have the time....

Best Regards,
Robert