Gareth, does the can of Ford Champagne Gold have as much pink in it as it looks in the pic? If so, it's actually pretty close to GM Evening Orchid.
And, on the grille subject. If you check the pics you posted, you'll see the actual grilles are black with the wide surrounds painted silver. I made the same mistake when I built the kit. But to my defense, I built mine over 30 years ago.
Man, where do the years go ?? LOL ?