Sorry for the confusion....What I meant was BA's equivalent naming of aircraft in the same way as Pan AM's famous ' Clippers '.
In the case of G-CIVF, it carried the name City of St Albans on the outside of the fuselage when it was flying in BA's previous blue / grey scheme, but I don't think it does now, no ?
So I'm assuming that when the BA aircraft were repainted into the current blue / white scheme, the ' fleet names ' were not painted on to the outside of the fuselage and the ' fleet names ' tradition quietly disappeared. Same thing happened at AF and AZ, which is what got us round to discussing BA as another example.
So I suppose the answer to my own question is that it would probably be which was the last BA aircraft to fly in the old blue / grey colour scheme before either being retired or repainted, perhaps.