I didn't :-(. But thanks for asking :-)

I've called all three airports, and BA, and nothing. My travel insurance are being very ambiguous as to whether they will cover the loss (since it was not checked in), so I have not purchased a replacement bag- I bought two pairs of trousers and some swimming trunks and made do without the rest. I will be travelling home with a carrier bag balanced on top of my hand luggage. As and when the travel insurance pays out, I will start looking for a replacement, although it looks like it's very hard to buy a "top bag" that attaches unless it's part of a "travel set".

Oh well, going home today, will see the kids tomorrow! All is good :-)

-simon