As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
OPERATOR NOTED (2) NON-STANDARD RIVETS INSTALLED ATTACHING THE PN 101-524017-4 RT RUDDER MECHANISM SUPPORT BRACKET ANGLE TO THE FS 437.234 CANTED BULKHEAD. DURING RIVET REPLACEMENT FOUND THAT IB RIVET HAD FORMED A SHOP HEAD BETWEEN THE BULKHEAD AND SUPPORT ANGLE DUE TO A MOUNTING GAP. (K)