take a pic of the ECU from above. The eeprom could have been removed and re-flashed but a commonly pirated program like the mugen one is nothing special. and for your reference the ECU would say 'PCT' instead of P73 if it was a EK9 ecu
Well Mugen ecu also uses JDM ITR ecus. Normally they would have the mugen ID number for each ecu and mugen stickers to go along... Otherwise it could just be Mugen chipped.