<<Formal Mmo was 2.04>> Not if you wanted the type rating (ground school taught 2.00) ...
But you would see more, and Mach #s in excess of Mmo for two reasons:
1) from the cabin the Marilake display was far from accurate (it had a big delay in it to stop it flaying around and on those hot days when we were struggling in the cruise climb a couple of hours of M1.98 would dissapoint the customers so it would read M2.00 - same for a "subsonic" charter - very common to see M1.00 on the Marilake if the true Mach had temporarily "bracketed" over the normal M0.95 subsonic cruise)
and 2) Concorde was designed to be flown right up to Vmo / Mmo at all times, and so small and regular excursions were common and part of the operation - it was not always easy to persuade the blunties running fleet audits that the overspeed warning was SOP and did not need an ASR, we'd have drowned in paperwork if so.....
Brgds
PS: O'Speed warning went off for:
Tmo +7 degrees C
Vmo +6kts
Mach >=0.95 with visor not locked up
Vc > 270kts with nose below 5 degrees
It didn't have a trigger for Mmo, but based itself on equivalent Vmo, FWIW