As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MCN - MAJOR REPAIR - DURING C19 CHECK DISCOVERED CORROSION ON FLOOR SUPPORT FROM BS 1006 TO BS 1016, BL 5L TO BL 10L AND WL 208. MAINTENANCE FOUND THE CORROSION TO BE OUT OF LIMITS IAW BOEING 737-300 SRM 53-60-51-1A1 FIG 101. REMOVED FLOOR SUPPORT AND INSTALLED NEW FLOOR SUPPORT FROM BS 1006 TO BS 1016, BL 5L TO BL 10L AND WL 208 IAW BOEING 737-300 SRM 51-40-02-0G FIG 12.