Many years ago, PCI gave this coin a red label problem slab. What grade and problem do you feel they gave on the label.
Looks lightly cleaned with just a little evidence of pvc damage. I guess PF63 Surface Damage edit to add Very nice coin!
Just curious. I see the fine lines on both sides. They seem to end and not go through the design details. I'm reading them as die polish lines.
The lines in the obverse field don't look like die polish lines but scratches. Otherwise a nice coin.
They are very light, and sometimes hard to detect when present on a "woodie" I see them on the jacket portrait and reverse devices.
I wouldn't hazard a guess on the grade number they assigned, and I'm not even sure they used this designation but for this coin I'd call it altered surfaces. Altered surfaces is a designation that can cover a lot of different territory, including the addition of something to the surface as well as removing something from the surface. And with this coin I think it was the latter, specifically dark coloration areas on the reverse fields. Here, to the left of the C - And here, under MERICA - And yeah, doing this could also be labeled as harsh/improper cleaning but there's kind of, I don't how else to define it, a fine line between altered surfaces and harsh/improper cleaning.
Some of those lines, especially the ones through LIBERTY, look like actual scratches. They might have been on the die -- but that wouldn't be my first guess. Those dark pits Lincoln's facing, though, look like corrosion scars.
I gave up trying to second guess TPG. If it were mine and I wanted it properly graded, I would send it to PCGS for grading and see what you get. For that coin, I think it would be well worth it.
I saw the purple the area looks smoothed. Isn't that also a characteristic of a later die stage? Those areas will also tone a slightly different shade because they are reflective, and a smoother surface?
That's a good way of describing it. That "smoothed" look is the result of altered surfaces. In effect the area is "rubbed" to try and make the darker color go away and reveal the lighter color (that we see now) underneath. It's been my experience that die wear (which is inevitable in later die stages) produces somewhat rough, almost bumpy at times, surfaces. Surfaces similar to those produced by a weak, or weaker strike. Toning is a function of luster, the more luster there is the more toning there will be, and the faster it will happen. The less luster there is the less toning there will be, and the slower it will happen. And since toning is progressive, the more of it there is and the longer it has been there, the darker it will get. And vice versa of course.
I'm not very knowledgeable on Lincoln matte proofs, but I would have thought the rims on the OP's coin would have been a pretty solid clue.