Let's elaborate on this a little.
I'm looking at 43 year old originals.
The black is flat and may be oxidized so, I cannot be certain that semi was not there originally. BUT, the black appears the same as the black on my nos taillight bezels that have only the slightest tinge of satin. So I do not know what to call it as it does not hold to typical satin finish as I know it. This "flat" black as I call it is also around the original grill r/t emblem from the car that was removed in '67 and stored.
Is there a chance there were different trim suppliers?
Now on the chrome area of the hood inserts, I cleaned it off with acetone.
The pins on the back side are definately shiny chrome plated.
I believe the inserts are made of pot metal that may have had the "sand-paper-like texture I described above then plated over to give it the sort of dull chrome finish, BUT, again I do not know if it is the chrome finish, or a paint over the chrome. If it's paint, the acetone did not remove it easily (I did not allow it to soak, just wiped over it.
Maybe someone that knows for certain how they were prepared can clear it up?