A 1942 penny is worth at least £1.53. Coins from the 1940's are very much in demand and their value is determined by the mint that manufactured or made the coin. It is also determined by the price of the silver contained in the coin.
1 Additional Answer
The value of the 1942 S coin is approximately £ 0.0186 in the UK and $ 0.03 in the US. The value of these ancient coins is based on the coin's condition. This means that those that are very worn out have a lesser value than those that slightly worn out.