You will find that the family Muscat is Italian and not Maltese. Just because a one individual family unit migrated to Malta, it does not make the "family" as a whole Maltese.
For example: You will find Niccolo Muskat was Podesta (Prefect) of Chios in 1380 indicating an family association with Genoa and not with Venice. There are numerous marriages over the years 1500-1700 between the families Muskat and Pisani. There were numerous Muskat families in Greece. It is possible the family "Mosco" is a name variation of Muskat which brings thousands of greeks in this family (Moschos, Moschpoulos, Moschatos, Moscholios, Moschonas, etc).
It could be related to the Napoli family Muscetolla.
Do your research properly.