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-21 CHECK FOUND TOP 3 OUTBOARD SCREW HOLES ON FIRST OFFICERS NR 1 WINDOW FRAME TO HAVE EVIDENCE OF CRACKING INSIDE HOLES. MAINTENANCE REMOVED CRACKED DOUBLER IAW BOEING 737-300 SRM 53-10-01-2 FIG 210. INSTALLED REPLACEMENT DOUBLER IAW BOEING 737-300 SRM 51-40-02-0 FIG 4.