Display shelf for lightweight things (floating, French cleat inspired)

Shelf for VERY lightweight models (most immediately: my growing collection of Metal Earth 3D laser cut models). Design constraint: I wanted no mounting hardware to be visible, but it had to be stronger than double-sided tape. Solution: a French cleat-style floating shelf. Two parts for one shelf system: the anchor to screw onto the wall and a shelf to hang off it. Two shelves sizes are provided: 50mm deep by 250mm long, and 80mm deep by 250mm long. The anchor thing works for either one. Aga