I don't think they could take very much with them. From what I know they left in quite a hurry, so beyond personal items and jewellery and what was in the palace safe, I would imagine they left with very little. Of course it would be very interesting to find out exactly how they managed to get the jewellery out, remembering that each piece was probably in a presentation case, thus increasing the bulk. Perhaps it was literally thrown in a suitcase before they left for the airport. But then the Greek Royal Family, given the historical insecurity of their position, would, I imagine, have had an "escape" plan. I also wonder if they had to leave any jewellery behind ? From all accounts they did not take silver, furniture or paintings when they left, I think this is made obvious by the subsequent legal battles King Constantine had to endure to regain his property. One can only imagine the anxiety and humiliation he had to go through.
A great deal of mystery surrounds the Greek Royal family, and the strange "on, off" relationship the Greeks have had with them since their inception.
I don't think we will ever find out..............but I remain intrigued by that tiara !!!