In general, semi-gloss black paint was the color of choice on surfaces not normally visible. When an item was dipped in semi-gloss black paint, it usually was a bit glossier than if the same paint was sprayed. That's conventional wisdom. Semi-gloss varied from 20 percent to 80 percent gloss - 20, 40, 60, 80 percent increments with flat and full gloss at either end (that's my paint guys capability). If you cannot dip the jack, find a paint vendor that can make a batch of no more than 40 percent gloss for spay gun use.
Jim