Other than pyjamas, I seldom kept anything from BA flights. Packs of Rothmans and bottles of bubbly were soon consumed.
However, my one Concorde flight (JKK-LHR) yielded two leather look A4 document cases, a Concorde Colibri ballpoint pen, a tiny silver container, (now lost), and stationery.
I have just celebrated getting the pen working again. Colibri don't do refills for this model any more, but fortunately one Parker refill fits it.
Whilst I understand the marketing/branding logic that CWS suggests, why give out freebies on Concorde? I always wanted to fly on it, and freebies would not help me/my employer, pay for the next flight.
You never got a Dulux dog just because you wanted one, you got one for buying more paint!!