As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CHANNEL CORROSION LOCATION: FLOOR SUPPORT CHANNEL LOCATED FROM STA 1500-1640 LBL 7.25 POS: AFT REMOVED FLOOR SUPPORT CHANNEL PER BAC DWG 146N5390 (492172) DRILLED UP REPLACEMENT FLOOR SUPPORT CHANNEL PER BAC DWG 146N5390. INSTALLED FLOOR SUPPORT CHANNEL PER B757 BAC DRAWING 146N5390.