As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE FS 440 FRAME INSTALLATION DID NOT MATCH THE CONFIGURATION FOUND IN S/B 737-53-1125. THE S/B REQUIRES INSTALLATION OF .2187 INCH FASTENERS AND THE FACTORY INSTALLATION INSTALLS .25 INCH FASTENERS. ERA 334319-14 ADDRESSES THIS CONDITION AND INSTALLS MS20470D8 FASTENERS. THIS WAS DISCOVERED AT HMV.