Convert from obolus [Ancient Rome] to ounce [troy]

Unit Definition (obolus [Ancient Rome])
The obolus [Ancient Rome] is a historic unit of weight or mass. The obol is a very small weight that originated as the weight of a tiny Greek coin. In Rome, the obolus was equal to 1/48 Roman ounce (uncia) or about 0.57 gram.

Unit Definition (ounce [troy])
The ounce [troy] is a second traditional unit of mass or weight. The troy ounce, traditionally used in pharmacy and jewelry, is 1/12 troy pound, 480 grains, or about 31.1035 grams. Thus the troy ounce equals 192/175 = 1.09714 avoirdupois ounces. This unit is the traditional measure for gold and other precious metals; in particular, the prices of gold and silver quoted in financial markets are the prices per troy ounce. The troy ounce is divided into 20 pennyweight or into 8 troy drams.