So basically the 500€ fine cannot be contested, and if I would win a court batte against the previous owner, the 750€ engineering cost will still not be paid by him, I would only get an apology letter from him and he would pay some to the court.

In addition to that the court would cost an additional 1000-2000€ minimum, so no thank you, I do not wish to be extorted more than necessary.

I will just pay the extortion demands and hopefully get away with no heart problems.