What was found
ENGINE NR 1 REV UNLK ILLUMINATED ON TAKEOFF ROLL, REJECTED TAKEOFF, WHEN THROTTLES PULLED TO IDLE REV UNLK LIGHT ENGINE NR 1 EXTINGUISHED. REJECTED TAKEOFF AT APPROX 6O KTS. REMOVED AND REPLACED NR 1 ENGINE PRESSURE REGULATING AND SHUTOFF VALVE AS PER AMM 78-31-05-4-03. OPS TEST OK, 78-13-11 P BLOCK 501. MOVED A/C TO TAXIWAY PERFORMED HIGH POWER RAN PER JRH. NO REV UNLOCK ILLUMINATION OCCUR. A/C OK. PREMATURE REMOVAL/INSTALLATION OFF MFG 3214236-8, POS 1, SRL P-236C, TAG 0519A3, ON MFG 3214236-8, SRL 369C TAG 6A9488.