I’m going to go with MS66. I almost guessed 67 but the dings & scratches around the face & bust seem too much for a 67.
Most likely a 65, but 66 is possible with modern grading standards. ANACS is sometimes low, so could be a 64 on the holder...a dart toss with ANACS.
Let's hope that this is not "the modern" MS-65 or 66. It has significant marks on the face. No way that is a "Gem Unc."
I voted 61 as there wasn't a lower choice. The coin looks "flat" and grey, as if it was dipped and not properly cleaned afterwards. The "bag" marks distract so the eye appeal for me is very low. I wouldn't throw it out of my bed, but I wouldn't pay for it either. JMHO
No matter what was wrong with the planchet (is this the word you were looking for?) the coin is far from BU. Luster is impaired or non-existent and there are a couple of hits on focal areas.
It doesn't matter what the composition is for a planchet to get mint luster after being struck. Some coins show it better than others and will show it better than others as they age.
I'm always looking to learn. Any particular reference you like that can explain the particulars to me as you understand them? EDIT: Well, I found a thread from here at CT from 2017.What's your take on the info in the thread? https://www.cointalk.com/threads/luster-a-guide-for-beginners.58435/
It should be obvious that different metals have different properties, which is why we use them. Additionally, the high speed mints also put pressure on the metal differently. Clad Ikes barely fill all the devices or stamp out the hard clad metal.
It is the break through on the reverse of the eagle's high points that really bother me, as if the strike just didn't make a smooth and clean impression in those spots.