Convert from fother [lead] to unze [Germany]

Unit Definition (fother [lead])
The fother is a traditional English unit of weight for lead. The fother, equal to 30 fotmals, was always a little smaller than a (long) ton. The original version seems to have been equivalent to 2160 avoirdupois pounds, and the version still being used in the nineteenth century was equal to 19.5 hundredweight or 2184 pounds.

Unit Definition (unze [Germany])
The unze is a traditional German weight unit, corresponding to the English ounce. The unze equals 1/16 pfund. Although the pfund has been assimilated into the metric system (as 500 grams), the unze is effectively obsolete. It varied in size from about 28 to 35 grams. The word comes directly from the Latin uncia; the plural is unzen.