Those were a semi-gloss polish on the anodized aluminum (basically a clear anodize).
The black is just matte black on every car I've ever seen. Is it organisol?
Yes brite dip anodized with a matte-semi not Organsol.
I would tape up all.the clear anodized part, and do a lite clean with common wipe down used to wpr cars down for paint. It will remove wax grease. Then scuff the black with a Gray 3M pad.
Then wipe with wipe down again before paint.
SEM makes spray cans and quarts of black
I will post my 1973 Dart Sport NOS ones and grille below
