The holes were not "punched" out at the factory.
Many times they were punched at the first brake job. If there was a slight lip on the drum, the adjuster could only be accessed by punching out that knock out. They do not need to be punched out if you already have it apart, and I would not do so.
Believe the self adjust lever was cad plated (not sure), but that is a rough environment, so they fade.
The park brake lever was natural, I believe, but again not 100% certain.