Convert from carat [international] to mercantile pound

Unit Definition (carat [international])
The carat [international] is a unit of mass used for diamonds and other precious stones. Originally spelled karat, the word comes from the Greek keration, a carob bean; carob beans were used as standards of weight and length in ancient Greece in much the same way barleycorns were used in old England. Traditionally the carat was equal to 4 grains. The definition of the grain differed from one country to another, but typically it was about 50 milligrams and thus the carat was about 200 milligrams.

Unit Definition (mercantile pound)
The mercantile pound is a historic English unit of weight, the mercantile pound (libra mercatoria) was the commercial predecessor of the avoirdupois pound. Used from about 1100 to 1300, the mercantile pound contained 15 troy ounces or 7200 grains. This is equivalent to about 1.0286 avoirdupois pounds or 466.55 grams.