Fair comment Doug - the scheme I described is the provisional plan, but it's not yet been done.
I'm on the Roubo trail Eiji (my current is a home made general purpose soft wood job on steel brackets), although the design in the Chris Schwarz book is the one (but with a thicker top) in mind so far with the top as close to 5in as I can get out of the planer from my stock...
ian