Convert from oncia [Italy] to as, ass [Northern Europe]

Unit Definition (oncia [Italy])
The onça, once, oncia, onza is traditional names for the ounce unit in Romance languages. The Italian oncia or onza is no longer used, but traditionally it equaled 1/12 libra or about 27.3 grams (0.96 ounce).

Unit Definition (as, ass [Northern Europe])
The as, ass [Northern Europe] is a traditional unit of mass for gold and silver, used in most of northern Europe but not in England. The unit varied in size from about 48 to 58 milligrams (0.75 to 0.90 English grain).