Does anyone have the formula for Ardent Silver? 

I have searched and found this link that says it is in Duplicolor: 

https://57fordsforever.com/smf/index.php?topic=4578.msg77545#msg77545

Hi Terry,

The color is Ford Argent.  Ford no longer sells it, and the suppliers are substituting.  The Duplicolor may be close and may be one of your only options.  The Thunderbird suppliers are selling Seymour Dull Aluminum paint as a substitute.  You can buy Ford Argent Wheel Paint but it has a metallic component to it. 

Thanks for giving me more information.  I was almost certain that Dupli color would be the way to go.  I don't need a perfect match as this is not "restored".