I am Catholic. I love my church, but one cannot be unrealistic about any of this.
1. If the Vatican was "holding" Gold, there is no reason that they should continue to.
2. It is none of the business of the US.
3. There is no reason to close our eyes to the mistakes made by the Vatican. JPII made it very clear that we are sorry and apologized for the wrongs. He led the way.
I have to do some reading on this whole situation. The little that I read, the Vatican's claim was that they were holding the assets for safekeeping. The owners are asking for it back. That is fair.
You're working from the premise that the gold is stolen.