As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
INSPECTION TYPE-C, MAIN CABIN FS 850 TO 870 BL 0 TO LBL 45 CENTER TANK UPPER PRESSURE SKIN HAS CORROSION. REMOVED AND AREA NOTED WAS SUBMITTED TO ENG FOR REPAIR. FLAP PEENING DAMAGE AREA PER DHC SK 904-400-AND BOEING M/M 20-10-3. ALODINE AND PRIMED STRUCTURE AND REINSTALLED FASTENERS PER SK 904-400 AND SRM 51-20-4.