The three tiers are now filled and crumb-coated. Awaiting final icing coat, stacking (aka engineering) and decorations. 3 layers in each tier, of vanilla spice cake and ivory-tinted buttercream icing.
Oh my gosh it's delish! (I baked an extra layer just in case I needed it -- but have only had to use it for sampling purposes, since the chef needs to KNOW that it tastes fabulous before ultimate presentation. Right?)
The bride saw it a few minutes ago, even in its unfinished state -- and pronouced it beautiful and delicious -- so I think we're good to go.