The cake actually isn't too hard, if you have a Larson Scanner...
This cake consists of 4 8" round layers, stacked with buttercream between each layer. The top 2 layers are on a cake round, with dowels below for support and stability.
I molded Rice Crispy Treats to make the crest and face plate. I cut a "window" for the Larson Scanner display.
Greg assembled the Larson Scanner from a kit (EvilMadScientist.com: http://evilmadscience.com/productsmenu/tinykitlist/152-scanner?qh=YToxOntpOjA7czo2OiJsYXJzb24iO30%3D) He used a fairly long wire for the battery pack, so the wire could wrap around the cake to the battery pack on the back of the cake board.
Greg also built a little shelf for the scanner from a thin piece of wood and encased it in a box made from a clear (grayish) plastic notebook divider page. I placed bamboo skewers between cake round (under the 3rd layer) and the cake layer, so they protruded to make a little shelf. I mounted the Larson Scanner on this shelf, placing the battery pack on cake board in the back.
I placed the rice crispy treat face place over the front and top of the caked, using liberal amount of buttercream to hold it in place.
I covered the whole thing in gray-tinted rolled fondant, with the wire emerging from the back of the cake at the very bottom. I covered the scanner with paper and sprayed the cake with edible silver spray color, to give it a shiny metallic look. Remove the paper, turn on the power, and voila!