It's probably located on either one of the door jambs for the MED or on the exterior of the aft fuselage. The L-1011 plates were riveted to the L/H #1 MED forward door frame., and 727-100's were in the aft airstair door jamb. I believe the FAA mandated several years ago that all large (over 12500#) aircraft needed an aft exterior mounted metal plate with msn c/n and registration # on the aft fuselage as I guess even they realized that an airplane rarely backs into the ground.
_________________ Don't make me go get my flying monkeys-
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