[Held for Ransom]

According to the assembly manual, the Firebird/Esprit models have an all argent silver grille (496286/496287). Like njsteve's Gramma car.
Formula and Trans Am had an Argent Silver grille with a black background (496284 and 496285).
But, I've seen ones like the third picture, just don't know if they were doctored or not.