It was privatised in early 87. By the time that I got my first Gold card - 89/90, not much had changed in terms of Service. Real prime beef and really good wine in 1st class. (Ch. Lynch Bages is one I remember).
Prices were steep, and the main users were the big corporates, who were globalising, travelling more and more to offices around the world.

Nowadays it is not even a full service airline. You need to fly with Aegean and others to experience that.

Back in the mid 70s, BA launched the "Shuttle". You got a full meal service on the London to Manchester flight from about the early 80s!!!!