Convert from hundredweight [short, US] to libra [ancient Rome]

Unit Definition (hundredweight [short, US])
The hundredweight is a traditional unit of weight equal to 1/20 ton. In the United States, where the currency was decimalized and there wasn't so much need to align the unit with the quintal and zentner, the hundredweight came to equal exactly 100 pounds (about 45.3592 kilograms). The U.S. hundredweight seems to have been invented by merchants around 1840. To distinguish the two hundredweight units, the British version is often called the long hundredweight and the American is called the short hundredweight or cental.

Unit Definition (libra [ancient Rome])
The libra [ancient Rome] is a traditional unit of weight. The libra was the Roman unit from which the English pound is descended; the symbol "lb" for the pound comes from this unit. The Roman libra contained only 12 unciae (ounces) and was about 0.722 English pound. The word "libra" is sometimes used now for the kilogram, a much larger unit.