What is the proper finish on the plastic surround, 70 cuda fwiw. Ours are slightly textured? Is that proper ?

They were a very fine wrinkle finish, not like the spray can type.
like what you'd fine on some machinist tools.
Looks like texture from a distance.

Lots of variation in the finish of those parts. I've seen some that had very little texture and others that had quite a bit. I used VHT wrinkle paint on mine and the finish is very close to what it originally was. Here is what mine looked like originally.

wrinkle i removed for repair and redo. vapor blasting took the paint off no problem.

I've used Harley Davidson Wrinkle Finish on mine and they look good. It's on the expensive side and there are cheaper alternatives (eg. Burdar's) out there.

A Texture finish & Wrinkle finish are 2 totally different types.
PPG never sold a wrinkle black lacquer.
But you could get a textured black lacquer.
Texture is by an additive.
Wrinkle is by how is dries.
Any spray can wrinkle I've used, never was like the black wrinkle from factory trim pcs.
It just sprays on too heavy & thick.
OEM finish was very thin.
Too many trim pcs these days have already been resprayed by can.
Factory didn't change how these were finished over the years,