My original 71 grille was all silver from the factory. The 72s I had and other 71's were blacked out. I had many cars and grilles. Some were molded in silver and then blacked out and some were molded in black and painted silver.
The grilles that were molded in black were never cracked at the trim screws were the molded in silver were. All the repop grilles are silver and blacked out.
The last 2 pictures you can see the grille was molded in black. What I can tell you is I sold many grilles and the molded in black were all big money never under $1500. I prefer the silver grille molded in black over the blacked out grille molded in silver. But that is just my preference