Do I have to rivet the grill back to the support brackets, or has anyone out there used screws or? Originality is not my main concern, since restoration project is a "modified" ordeal.

I used small carriage bolts to hold the new grill on one of my 65s. The heads were only slightly larger in diameter than the original rivets. It still maintained the look of an original rivet, unlike most of your generic rivets that have a hole in the center. Gonna do it on my 65 resto project too. Looked very nice.

Thanks for the tip.