Now that I'm back home reunited with my books I could give you a bit more info. East India Co. operated on Sumatra island for a period 1685 - 1824 after which it was driven out by the Dutch. In 1804 four keping coins were struck on thick and thin planchets; thin, 8.50 grams (apparently what you have), being more scarce thus worth more. In the condition that you have it could be up to US $9, according to Krause catalog.