What bugs me is that this 1910 does have some weak squared rims, not as thick as my 1912 matte proof. But the edge is squared and polished from what I can tell through the edge view holder.
If it has all the diagnostics it is worth submitting. Some of the markers are on the master die, which would be seen on coins struck for circulation. From what you say yours also has the markers that are seen only on the matte proof. Does it even have the filled S on the reverse from PLURIBUS? The only question now is if it were struck from proof dies as NGC suggests. Did they even consider this being an MPL when it was in the grading room or was it after you raised the question after having it in hand? I would try PCGS. You may receive the same result, but at least you can submit it as a proof. Then they will be aware to look for the markers.
I was unable to tell about the S in PLURIBUS. There is some gunk in the loops. I believe that is correct. That the coin was submitted as a business strike and was never bothered to be looked at as a matte proof. In their return email to me they atleast admit Im half way correct. And im sure they only showed a grader my pictures, and was reluctant to give a definitive answer. Also probably didnt enjoy my slight bash on their picture taking abilities. This is what they show in their database. Now im not expecting true view quality but jeesh, the coin is no where near that dark.
Ive decided to crack it out and send it to PCGS. Ill see if I can get some pictures of the edge once its out.
Yeah i have all sorts of ways to crack one open. My easiest and cleanest way is with a vice. Apply pressure evenly end to end, side to side, usually breaks right around the seal. Although I dont think I have cracked out one of these newer NGC slabs before.
It will be a couple of weeks before I send it out. Kinda blew my coin budget with some other purchases lol
I have a feeling this coin is going to come down to coiner's intent. The die weakness on PLU in PLURIBUS is worrisome. I have examined a lot of 1910 MPLs and haven't seen one with this late of a die state. Either this coin comes back as a matte proof or it becomes the best evidence I have ever seen of matte proof dies used to strike business strikes.
I wouldn't be too concerned over the PLURIBUS if all the other diagnostics are there. The PLU is also weak on mine.
My concern would be the flat edge of the rims. Yours do seem to be a little beveled on the edges instead of a straight 90º angle. On the photo where the coin is standing on the rim you can see a shadow on the left side which shows a little bit of 45º angle.
Yeah I noticed that too. On the obverse between 5 and 7 o'clock the rim is a bit thin as well but yet a fin is present. The bevel is definitely on the obverse side. The reverse looks good. I don't know. I can spot a matte proof pretty well, but this one is tough. Heck here's an example of the seller pics. I could tell it was different and I could just barely see the line through the E in WE but that was it. It was under 100 bucks, figured it was worth a shot and so far it has been.