Thanks for the idea's on fastening the top with wooden cleats glued to the underside of the granite.
Although it is not finished, it was far enough along to be useable and present to SWMBO for Christmas, so I moved it into the kitchen for her to use during the Holidays, and until I get the drawer and drawer assembly done later this week.
Page 4, Projects Journal on the website below.
As it turns out, the cleats work fine as placement guides for the top, and to keep it from moving about. And, as Andy indicated, the top is heavy enough that it will not be necessary to actually screw the cleats to the aprons.
Not a bad idea for the top to 'float', as the combined weight makes moving this thing a task and the ability to easily remove the top is welcome.