What was found
FUME EXPOSURE DURING DESCENT, A DRY MUSTY ODOR WAS NOTICED THROUGHOUT THE CABIN AND COCKPIT. REMOVED AND REPLACED THE RECIRCULATION FILTERS AS A PRECAUTION, NO FUMES NOTED IN THE CABIN & COCKPIT AT THIS TIME. IAW AMM 21-21-41 PB 401. PERFORMED BORESCOPE OF THE NR 1 ENGINE FOR OIL WETTING AT THE 6 O'CLOCK POSTION. NO OIL WETTING NOTED IAW AMM 72-31-00-290-002-A. PERFORMED BORESCOPE OF THE NR 2 ENGINE FOR OIL WETTING AT THE 6 O'CLOCK POSITION. NO OIL WETTING NOTED IAW AMM 72-31-00-290-002-A. OPS CHECK FLIGHT AND POST FLIGHT WALK AROUND PERFORMED AND FOUND SATISFACTORY. ACFT RELEASED FOR SERVICE.