That is splendid!
But for you Anglican Use Catholics wouldn't it be the Duke (King) of Bavaria -- the rightful Jacobite claimant to the English throne? (stirring the pot...)
Well, I say King Juan Carlos based on territorial considerations, but you are right, emotionally I would be for the Jacobite claimant.
I do belong, as one of the scruffy Catholic auxiliaries, to the Society of King Charles the Martyr, the Catholic patron of which is Fr. Jean Marie Charles-Roux, IC, whom you may remember as one of the priests who said the TLM for Mel Gibson on the set of the "Passion", and later gave a couple of very interesting interviews to "Inside the Vatican". He had been stationed at St Etheldreda's in London for quite some time before going back to the mother house of the Rosminians in Rome, where he met up with Mel.