Convert from obolos [Ancient Greece] to oka, oke [Turkey]

Unit Definition (obolos [Ancient Greece])
The obolos [Ancient Greece] 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 ancient Greece the obolos was equal to 1/6 drachma, or roughly half a gram (8 grains).

Unit Definition (oka, oke [Turkey])
The oka, oke [Turkey] is a traditional unit of weight in Turkey and throughout the eastern Mediterranean. The oka is approximately 2.8 pounds or 1.28 kilograms, although its size varied somewhat over the large area formerly included in the Turkish empire.