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-19 CHECK A 2 INCH CRACK WAS FOUND IN INTERCOSTAL AT RBL 50, BETWEEN BS 344 AND BS 360. MAINTENANCE REMOVED CRACKED INTERCOSTAL AT RBL 50, FROM BS 344 TO BS 360; FABRICATED A NEW REPLACEMENT INTERCOSTAL PER DWG 65-45834; INSTALLED REPAIR PART IAW B737-300 SRM 51-40-02 FIG 8 & 12.