Thoughtful of you, thank you.
I called in to my local Goldsmiths earlier today and while chatting they offered me a bi-metal SD.
Not something I'm interested in, and I've no idea how easy these are to find, but if anyone's interested, I'm pretty sure it's still available and would be happy to see if I can help them get it - PM me.
There was one in the window of Harrods on Saturday….