Don ... you are opening a real can of worms here.
think back at recent notes of fairing keels where lead is planed off the keel to achieve template exactness. We are probably looking at various keel weights depending on which day of the week the keel was cast. and it sounds like we are talking borderline amounts of keel weight that put our "Official" specs in trouble.
But what the measurer didn't mention is that the later cockpit configuration with a larger open area is also a negative in regard to water drainage. In a real hard rain ... i've been up to my ankles in water draining too slowly out of the cockpit drains. I'm thinking there are two measurements involved and the original configuration may make it.
