As a matter of fact ONB
I saw the same Concorde at 1812, but at Mitcham, quite close to Croydon. Indeed the gear was down and I saw it turn on to finals at about 14/18 miles.
BA 2 has been landing at 2105 (ish) but used to land at about 1720 (ish). The second JFK might just about be ready to start - maybe, PERHAPS!