Regarding the identity of the Sovereign Grand Master:
John Chapelle Paleologo is a Maltese noble holding the title of 10th Count Ciantar-Paleologo and Prince of Mistra (in Greece). The claim is that the Order became 'discrete' in the 15th century, but that the position of Grand Master has always been passed down to the oldest male heir.
In conclusion, the order is still not a recognised secular or religious order despite this additional information. The Crown upon the insignia is identical to the one seen on the Orders of Military and Civil Merit of Bulgaria (during the monarchy), suggesting a claim of a sovereign house under the Byzantine Empire (which is plainly not the case).
May she defend our laws, and ever give us cause, to sing with heart and voice, God save the Queen.