I can tell you the British Airways procedures for the unlikely event
of rapid decompression: They were pretty standard other than O2 pressures and fuel xfer for CG purposes.
Cut the warning bell
Crew O2 maks on and @ 100%
Switch Comms mike to mask
Confirm Warning
O2 showing deployed for cabin
If no pressurization control possible then the ops manual calls for:
Emerg Descent
Fuel Xfer (FWD) on override (CG issues)
.........
...............
The PAX O2 regulator goes to 90 psi above FL180.
The above is reference the BA Concorde AFM.
It would be very interesting to hear about actual experiences on this event.