As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE FLIGHT CREW REPORTED THAT DURING PREFLIGHT CHECKS IT WAS DISCOVERED THE PILOTS OXYGEN MASK GOGGLE PURGE LEVER WAS MISSING. THE BASE MAINTENANCE TEAM REMOVED AND REPLACED THE MASK WITH AN OVERHAULED UNIT. OPS CHECKS WERE GOOD. THE AIRCRAFT WAS RETURNED TO SERVICE.