As Devlyn said I am not a legal professional but I would think especially after a judge said that your father didn't have to be informed that there is no way he can get it changed. Even if he could find a radical judge to try to change your name back, I would think that it would have to be an appeals judge. If you have a judge overturning the judgement of an equal level judge that would set a bad precedent.
Your father has very shaky legal grounds to even try to fight this. As an absentee parent he is fighting against both you and your legal guardians wishes, I would say that is darn near impossible for him to win.