Oh, please spare me. You haven't bought ino that myth have you? Read my previous posts, or any good book on the subject, or the original 1816 report by the British Government themselves that denounced the acquisition as one of theft ... and AFTER thatm THEN explain to me how they were perserved ..
Let's see, Emma old girl, would you rather the Elgin Marbles were in the British Museum, or in some peasant's garden, semi destroyed and unknow, some Turk's garden, later destroyed by WW I bombs, or perhaps sort of still on the Acropolis, but damaged beyond repair and recognition ? Those are the obvious places they could be.
How were they preserved ? Goodness gracious, if you don't know/understand that, then there's no hope at all, that my explination would help you any. LOL