But which one?
Twenty three days after BA was formed in April 1974 the penultimate was retired and the final one a couple of months later.
No Vanguard wore full BA livery.
I have a pic partly showing it but not the registration.
I don't think (guess)

There had been a gradual shift toward BA identity for about two years before with the first visible changes happening before the official merge so it is possible it was the one retired in March.
So if anyone has a pic of this aircraft with the titles or knows which one it was I would be able to get that one done
Garry