Convert from tod to firkin [butter, soap]

Unit Definition (tod)
The tod is a traditional unit of weight equal to 2 stone or 1 quarter. The tod is thus equivalent to 28 pounds or about 12.7 kilograms. "Tod" is an old German word meaning a load.

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).