Originally Posted by
WHBM
Just to double-nitpick here, that's not the original livery, Mexicana received their 4Cs in 1960, then in 1962 they entered into a charter agreement with Aerovias Guest who had a once weekly schedule with Constellations to Lisbon, Madrid and Paris, which had become uncompetitive by then. Guest were also out of money, so the charter, and the dual titles on one aircraft, were arranged. I believe Guest crews were trained and they may have put the Comet on the first leg of the flight, Mexico City to Miami, but Guest went under before the jet service to Europe could start.
That sounds about right - the photo is reportedly dated May 1961.
There is a later version of the livery with a solid blue cheat line which the Comets also wore, plus various photos of models featuring the stylised "M" on the tail, though I can't find any evidence that the Comets actually wore that.