After the curves were shaped, the steps were cut into the center piece and then the cheeks were glued to the sides.

Here you can see the brass feet attached to the legs.

B5 loves their details... the legs, have brass feet, and the feet have toes, of course.

This is where it gets fun!  Each leaf rests on brass arms that pull out from under the table top.  The arms are hidden in oak runners behind the apron.

The eight oak runners and brass rails should all have the same travel so that the leaves are interchangeable.

More details.. here you can see how the brass runs through the apron.  B5 also designed a gorgeous rest and pull at the end of each brass arm.  Highly functional, these ovoids provide surface area for the leaves to sit and a comfortable pull to draw forth the brass arms.

With a leaf placed between two rails you can see the engineering.  In the middle of the leaf is a disc that swivels under the main table top where it is screwed down to lock it in place.

I marked the arc of the hole through which the disc is attached to the table.  The screw is to be located at the apex of the arc.

Of course it's not a screw... a knurled knob is used.  It is screwed into a threaded insert.

A close up from the side shows how clean the design is... nothing gives away the functionality hiding behind the apron.

Here we see how the leaves are located around the table on the brass arms.
 

The monster.. seating 14, you'll need to make some more friends to fill it.