Aaah, I understand this already. Sorry, I should have been more clear.
I meant the '71-72 3-piece models only. I know about the "Basic" models, but I put that in quotation marks as I've seen some of those that have the 3-piece grille, but minimal equipment. The more in line with the U.S Basic model, I suppose.
Now, what I mean by chrome/Silver surrounds are these:
http://www.flickr.com/photos/sven_designs/3733440369
Compared to the ones in your post, these are silver (Unpainted, as you said). What I'm wondering is why some cars have painted surrounds, while others are unpainted.