2004 Explorer, XLT, Flex Fuel -no crank , no start

I bought a 2004 XLT with V6 FFV. No crank, no start. Squirrels chewed up engine wiring harness and that was supposed to fix problem. Did not. Mechanic feels it the ECM and or keys, PATS. Ordering new ECM BUT the vendor is sending ECM already flashed with two uncut keys that has a different part number than the unit thats on there now.

Do part numbers change over time, vendor insists this is the correct part number for replacement: 4L2A-12A650-MG, LBO-526,LBO 527 and is what is called for for this VIN #.

ECM currently on the unit 4U7Z12A650L-FARM.

Does anyone know whether these are interchangeable or if the vendor is correct.

thanks