Hey, Jan; wouldn't it have been easier to stick a Saphir hull and deck on the new fin
I must say, though, that the removeable fin is a slick idea and my "coffin" could have been reduced in size had I had a look at the way things are done in the Netherlands first.
Btw, a question for you. Do your compatriots find 10Kg/cm torque enough for the Safir (that's the rating of mine on 4.8 V) or would uprating the battery to 6 V be recommended.
Martin