WHAT IF... LOUIS XVII ANIMATED MUSICAL?

In the 1990s, as a child, I saw the well-known animated musical that chronicled the possible destiny of the missing czarevna Anastasia Nikolayevna Romanova, who had disappeared in the wake of the Revolution.
In the film, an amnesic Anastasia, raised as "Anna" or "Anya" in an orphanage in the provinces, leaves for Leningrad upon coming of age, during the Roaring Twenties, and there meets trickster Vladimir and his nephew Dimitri, with the plan of bringing an allegedly "fake" czarevna to her grandmother Maria in Paris. During the journey westward, Anastasia regains her memories and identity, gradually falling in love with Dimitri and viceversa. The reunion between Maria and her estranged granddaughter (whom the old royal believes, at first, to be an impostor like many others), carried out by the reunion of a music box with the key that Anastasia has been wearing around her neck for all this time, moved me to tears.
Legend has it, Anastasia lived the rest of her life as a private person in either Paris or Berlin. May it be true?
Only the gods know...

The case of Anastasia Romanova has a spear counterpart in Louis XVII, the missing dauphin who disappeared after losing both his parents to the French Revolution. While his older sister Theresa successfully made it to her Habsburg relatives at the Austrian court, Louis vanished, like into thin air, into the tumult of Reign-of-Terror-era Paris. Decades later, many young men officially claimed to be the dauphin: tricksters, streetrats, farm boys, child soldiers and sailors...

There is a hypothesis, which I second, connecting the disapperance of Louis XVII with the equally mysterious sudden appearance of a pre-teen boy in the main square of Nuremberg, a decade later. Kaspar Hauser, as he would be known, showed evidence of having been exposed to severe abuse, and he could merely say but a few words in German...

Louis and his older sister in happier days, at Versailles.

Last portrait of the prince in the tower, shortly before his mother's death

and his own disappearance.

Kaspar Hauser, the lad from Nuremberg...

was he really the missing dauphin?

A child Louis led away from his mother's execution

in the anime Rose de Versailles/Lady Oscar.

My animated musical would have this Louis XVII.

I have got the idea of a 1990s-style animated musical based upon Louis XVII and his possible second life as Kaspar Hauser. An idea that dates back to my mid-teenage years, when I started taking to history.

My dreamcast would include (voice actors):

Louis XVII (child)...........................................Daniel Huttlestone

Kaspar Hauser (youth/young adult).....................................Eddie Redmayne

Marie Antoinette (cameo, the film will start with her execution).............Cate Blanchett

Maria Theresa.......................................Emma Watson

Friedrich Daumer (Kaspar's guardian in Nuremberg)...........................Jason Isaacs