Note that in a common law system, this would be thrown out of court under either "acquiescence" (if you don't raise a fuss for a very long time when someone unknowingly infringes your rights, you can lose those rights), or "laches" (if you wait long enough to make a legal claim that the defendant is injured by e.g. having made economic decisions in ignorance of that claim). Not sure about the equivalent Italian law,…
It's actually in the constitution: hereditary titles are no longer recognized.