might want to PM a Mod to move this to the Props forum.
I and a couple others have spoke about it, only one person I know has done one, using an off-the-shelf mesh product for the key's vanes.
I've taken tons of screen caps and produced 2 prototypes in styrene and brass, but the quality was very rough.
Backtracked and am doing some digital diagrams with the intent to photo-etch the vanes.