Be careful; we all know there is a lot of Artificial Toning going on. These AT guys can change the color without messing up the luster, so that is an important exception to my method above. AT is deceptive with modern coinage, but looks really hokey on early copper so it's easily noticed. For that reason, the method above is fairly reliable. Always keep the Thinking Caps on ! Generalities are dangerous, and there are often exceptions to the rules.
Based on the Grading Standards guide, I would grade this as a F-15, or F+. I love this coin, but the reason it would not grade VF-20 is the "balance of hair to left of eye" is not distinct. So it is very close to VF. This was a very nice find, congrats.