The "Whole Nine Yards" goes back a lot further than WWII.
There are two plausible explanations that I have heard.
One refers to the nine yard-arms on a major fighting ship under sail and the second to the amount of material required to make an adult male kilt. In hard times Scotsmen had to economise with less but whenever possible they would "go the whole nine yards" - later used to imply total effort or suchlike.