AEO - thanks.
I'm surprised in this day and age of everything being designed down to the nth degree that you can just stick a new design of blade (a fairly fundamental structure of a helo) onto an existing cab (Merlin) and it will work. I'm not doubting it will work. Presume it's down to developments in computer technology although I'd love to believe someone's being tinkering in a musty old wooden shed for months and produced a revolutionary design!