There may be some differences in years, as far as paint/no paint on some items....it may also depend on how drunk, or hung-over the parts painters were that day!
It is well documented that not all engines received complete coverage of paint on the lines...the engines were painted as they moved along the line, just a foot or so off the floor. Some of them didn't get any paint on the very bottoms of the oil pans....
I did shoot a light coat of flat black on my control arm shafts when I did the chassis on the '74, and then I rubbed it with a rag to make it not look painted, it's more of a dark, gunmetal greyish color....it turned out ok like that, but you can tell it is not a natural, cast finish.