Jobu - Have you done a compression test yet?
If your motor has steel sleeves, then it's been rebuilt. 2.4L 200's were all chrome bore motors from the factory.
If it has a rebuilt powerhead . . . it's possible that they dropped on a 2.5L powerhead.
The scoring or aluminum transfer is disturbing and it's likely the ring on that piston is stuck or that the motor got really HOT at one time. If you can catch your fingernail on any of the scratches/grooves . . . that's not good and you want to tear down that motor.
Steel:
Chrome:
2.5L Motor: (notice the behind the liner porting.
