What was found
MCN - C-21 CK - "C" - FUSELAGE SKIN BULGE AND CUPPED FASTENERS IN SKIN AT BS 977, BETWEEN STR 23R TO 24R. MAINTENANCE REMOVER FASTENERS IN SKIN, NO CORROSION FOUND ON FUSELAGE SKIN, HOWEVER FOUND SHEAR TIE CORRODED BS 965, RBL 20. REMOVED AND REPLACED SHEAR TIE BS 965, RBL 20 IAW B737 SRM 51-30-2.