The scoop is one piece of bent 1/16th" thick styrene. Here's a pic of it before installing.

The rest of the bottom is two layers of styrene over ribs that create the shape. The first layer is 1/16th inch thick over the ribs and the second layer is .75mm for the finish surface. The 1/16 layer stops short fo the edge and the second goes all the way to the edge.  I wanted the edge of the disc to be as thin as possible.

This is the just the first layer of styrene.