I have managed to find three of these beauties on my hunt for treasure! I love to find them because of the fascinating history attached to them. This particular coin was found in the front yard of a 1923 Sears and Robuck house in Missouri.

World War II prompted the rationing of many commodities. Nickel was highly valued for use in armor plating, and Congress ordered the removal of this metal from the five-cent piece, effective October 8, 1942. From that date, and lasting through the end of 1945, five-cent pieces bore the regular design but were minted from an alloy of copper, silver and manganese. It was anticipated that these emergency coins would be withdrawn from circulation after the war, so a prominent distinguishing feature was added. Coins from all three mints bore very large mintmarks above the dome of Monticello, and the letter 'P' was used as a mintmark for the first time on a U. S. coin.

Value

The "Year" column lists the year and mint mark on the coin -- D is for Denver, S is for San Francisco, and P is for Philadelphia. A coin without a mint mark means it was also minted in Philadelphia. The "Mintage" column is the number of coins struck and released by the U.S. Mint. The "Numismatic Value Range" column represents what people typically pay for that type of coin (usually a very wide price range depending on the condition).

Year Mintage Numismatic Value Range
1942 P 57,873,000 $1.00 - $95.00
1942 S 32,900,000 $1.00 - $200.00
1943 P 271,165,000 $1.00 - $70.00
1943 D 15,294,000 $1.00 - $70.00
1943 S 104,060,000 $1.00 - $100.00
1943/2 P unknown $30.00 - $2000.00
1944 P 119,150,000 $1.00 - $200.00
1944 D 32,309,000 $1.00 - $50.00
1944 S 21,640,000 $1.00 - $400.00
1945 P 119,408,100 $1.00 - $200.00
1945 D 37,158,000 $1.00 - $60.00
1945 S 58,939,000 $1.00 - $700.00

Source - http://www.coinflation.com/coins/1942-1945-Silver-War-Nickel-Value.html