Did a bit of research on this for our BN2 resto. The grill was originally a 'flat' chrome, which if it was paint might be called 'satin.' Have heard it referred to as 'butler chrome,' as chrome bits would dull a bit after repeated polishings by the butler (I'm sure your butler has better things to do, like change your oil, etc.). Some chromers can do this--ours did a reasonably good job--but you could also have it 'shiny' chromed, then hit it lightly with a media blaster with a soft media (soda, walnut shells, etc.).
The surrounds are regular 'shiny' chrome.