I know exactly what you mean Clive and ordinarily I would agree with someone with vastly greater knowledge and experience, but it just looks too.........'classy' for a drain. The aperture is a rounded rectangle, very wave guide in nature and that vane is beautifully made, whatever it was made of. The only thing is, I'm a bit concerned the aperture is not covered in some way.
Somebody, somewhere must know what it is and now I'm fascinated.
