Ah well they were just 747 crew for a while although there was a separate fleet with Tri-stars/747 dual fleet (known as the 'no jacket required' fleet due to their insistence on doing their own thing). When I first started flying there were 3 fleets, WW LHR (ex BOAC) was 747's, there was a Tri-star fleet and then NBA (short-haul ex BEA) had 737's and 757's.
Each new a/c and airline we buy tends to mess things up for a while! I'm sure BMI will bring something new to the party (and TAP too if that rumour is true).