Thanks AndyTom
I've probably got a RHD one, but it'll look upside down on your car.
There's this, though:
https://www.palace-de-lancienne.com/products/interrupteur-de-degivrage-arriere-dernier-model/
Thank you for your offer.I think I've got a spare one I took from a car in a scrapyard here.
Shouldn't be too much expensive to send.