Convert from firkin [butter, soap] to seer [Pakistan]

Unit Definition (firkin [butter, soap])
The firkin [butter, soap] is a traditional unit of weight for butter and soap, equal to 4 stone or 56 pounds (about 25.40 kilograms).

Unit Definition (seer [Pakistan])
The seer [Pakistan] is a traditional weight unit in India and South Asia. In Pakistan, the seer is now considered equal to the kilogram. The unit is sometimes spelled ser.