What was found
O2 MASKS IN SUPERNUMRARY SEATS #2#3#4 INOP. MOVED #3 O2 MASK TO F/O P/N MC10-25-104 S/N B126S41 F/O OLD MASK MOVED TO # 3 POS P/N MC10-08-109 S/N 121011(<P>ITEM TRANSFERRED TO MDDR 142132 PER MEL 25-25-03 DUE DATE 08JUN21. </P><P>REF LP1017426 ITEM 1: REMOVED AND REPLACED SUPERNUMERARY O2 MASK P/N MC10-08-109 S/N 121011 IAW AMM 35-11-51. OPS CK ALL SUPERNUMERARY O2 MASKS IAW AMM 35-11-00. ALL OPS NORMAL. THIS CLEARS DMI # 142132. PLACARD REMOVED, MCC NOTIFIED.</P>)