For those like John who manage to find many British coins pre 1920 the silver coins are 92.5% silver, 7.5% copper. 1920-1946 only 50% silver...from then on 'silver' became cupro-nickel.
I assume you mean the U.S. copper penny. Only 40 produced (something to do with the machine still having some copper blanks in it when the switch to steel was made).
I think the highest amount paid for 1943 was either 84 or 86,000 $ , this has led to earlier coins being redated and sold on as genuine.