Convert from fother [lead] to seer [India]

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 (seer [India])
The seer [India] is a traditional weight unit in India and South Asia. The seer equals 1/40 maund, and, like the maund, it varied considerably from one area to another. The official size in British India was 2.057 15 pounds or 0.9331 kilogram. The unit is sometimes spelled ser.