Convert from mercantile pound to carat [UK]

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.

Unit Definition (carat [UK])
The carat [UK] is a unit of mass used for diamonds and other precious stones. In the U. S. and Britian, the diamond carat was formerly defined by law to be 3.2 troy grains, which is about 207 milligrams.