I haven't heard of this but there was last year a sale of Sabena items at the airport, it lasted a few days. You could get anything you wanted including pens, glasses, models and even First Class seats. I was there last year and I got there a catalog with paintings from Magritte, a Belgian painter.
About the seats, six years ago I was at a collectible show in Brussels and there were three seats coming from the pax cabin of a Caravelle aircraft. You could buy all three for 5000 Bef at that time (125 Euros).
It's always a pleasure to spend time at these conventions.