Convert from libra [ancient Rome] to packen [Russia]

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.

Unit Definition (packen [Russia])
The packen is a traditional Russian unit of weight equal to 1200 funte, 30 pudi, 1083 pounds, or 491.4 kilograms.