As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT FL 360 THE STANDBY ALTIMETER WAS READING 300 FEET HIGHER THAN THE CAPTAIN AND FO ALTIMETERS. AT LOWER ALTITUDES IT RETURNED TO NORMAL. REF GMM 12-7-600. STANDBY ALTIMETER, CREW REPORTED MAIN ALTIMETERS OPS NORMAL. REMOVED AND REPLACED STANDBY ALTIMETER IAW M/M 34-12- 22-04. OPS CHECKS NORMAL AT THIS TIME. OK FOR SERVICE.