As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING C13 CHECK DISCOVERED CORROSION AROUND NUTPLATE ON FLOOR ATTACHMENT INTERCOSTAL AT BS 960, WL 208.1 AND BL 20L. MAINTENANCE REMOVED CORROSION AND FOUND TO BE OUT OF LIMITS IAW BOEING 737-300 SRM 53-60-51-1A1 FIG 101. REMOVED AND INSTALLED NEW INTERCOSTAL AT BS 960, WL 208.1 AND BL 20L IAW BOEING 737-300 SRM 51-40-02-0G AND 51-40-05-0G.