All these years and apparently no correct "brushed chrome" and correct fitting reproduction header chrome has been produced for '68 Firebirds and Camaros.
For comparison, below is a photo of the end of my original '68 header chrome showing the finish and non-brushed ear. I gave up trying to find correct originals long ago so I periodically refinish the "brushed" area with a silver paint to make it look somewhat better. I still cannot tell if the dull "brushed" area is a different plating, roughed up, or a very robust sprayed-on coating.
I recalled this discussion of the issue from a few years back:
re chrome topic