Watch List notes:

PERAK: Anonymous, tin ingot "bidor" (848g), SS-27, ornamental design based on the 'tampok manggis' or mangosteen rosette, EF, RRR. In Perak it became the practice to price all merchandise in smaller tin ingots called "bidor." The weight of 1 kati (605g) was equivalent to 25 cents (2 reales) of the Spanish silver dollar (8 reales). Gradually the term "bidor" became so popular that most of the tin ingots of Perak, irrespective of their weight, came to be called "bidor." These currency blocks of tin ingots were used for internal trade as well as in international commerce.These tin ingots continued to circulate until the mid 1850's when they were gradually replaced by the minor coinages of the Dutch and British East India Companies.

Estimate: 250-350 USD