Finding copper and bronze from the tropics in decent grades can be a nightmare, even supposedly common pieces with very low value in Krause take the 2 cents Eastern Caribbean Group - these penny sized coins were issued 1955, 1957, 1958, 1960-1965, Only 1955, 1965 and proofs were ever offered to the coin trade before going into circulation (these are cheap and plentiful in high grade) the rest are very hard to find