So you know how I feel!
Panic over. found them on a couple of websites and then they appeared in the Lufthansa World Shop ( clearly I had not looked hard enough) and they still available. I am a happy bunny.
Just realised that using Miles to buy a flight is not always the most efficient use of Miles as cheaper LOCos makes the Taxes and Charges added onto Miles bookings look expensive. So we have used our miles to buy the luggage.
Happy New Year!