As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MCN - MAJOR REPAIR - DURING C-18 CHECK 2 EACH CRACKS WERE FOUND IN RIVET HOLES OF NR 4 SLAT LOWER SKIN AT TEE CHORD AFT RIVET ROW SLAT STA 94.00. MAINTENANCE CUT OUT DAMAGED AREA OF NR 4 SLAT LOWER SKIN AT SS 94.00; FABRICATED A REPAIR FILLER AND SPLICE PLATE; INSTALLED REPAIR PARTS IAW B737-300 SRM 57-43-01 FIG 206.