i hate to be the one to bring the bad news, but if the coin in the picture is the "war nickel" you found, it isn't...
Sure wartime nickels were minted from 1942-1945, but in the year 1942, they made regular nickels(the one pictured above) and wartime nickels...
A war nickel can be determined by spotting a LARGE mintmark(P, D or S) above the dome on the back of the nickel... note: 1942D nickels are not war nickels.