Would this part fall under the rule that different shades of SGB is a good thing ? 
Simply put, yes. Some parts were dipped, others sprayed, as was the engine compartment. Without any source, I would (if possible) consider a range of 20 to 40 present semi-gloss black as a goal. Different manufactures of rattle can semi-gloss black might work. I have a couple of quarts of semi-gloss black I had specially mixed in the 40 percent range to make the difference obvious.
Jim
