The MRBR is the only document apart from MPD Section 9 that is approved by the FAA. The signatures for the MRBR are Boeing, FAA, EASA and the Canadian authorities l believe.
The tasks in the MRBR are the minimum that is required by a new start up airline, most airlines will also carry out all the task listed in the MRBR. These tasks are all derived from the ATA Airline/Manufacture Maintenance Program Planning Document using MSG-3 analysis also listing their MSG-3 Failure effect categories and intervals.
The MPD has all the tasks from the MRBR, plus other tasks over the years which Boeing and engine manufactures suggest or recommend that an operator should carry out. The MPD will also include SB inspections and some AD tasks if there is no terminating action for the AD. The MPD will also include tasks from the CMP (ETOPS manual) but Boeing is now starting to remove these and some SB tasks from the MPD. Section 9 of the MPD has all the mandatory inspections for systems and structure and the new fuel AWLs listed, this is why it is the only part of the MPD that is approved by the FAA. The MPD also has extra info in the way of man hours, as if my memory serves me the MRBR does not.
One difference is MRBR tasks generally can have their intervals extended over time by both Boeing and the airlines, MPD Section 9 intervals can only be extended by Boeing with the FAA and EASA agreement.
Many USA operators do not make use of the MPD and base their AMS or AMP on the MRBR and MPD Section 9 only.
As for the OAMP l can not help.
Hope this is of some use to you.
