i think what looks like a stain is just shadow from the holder. you have to remember we are looking at a coin via photos. its extremely difficult to capture what any coin looks like in hand as we can't rotate is proper lighting. the best we can do is, based on knowledge base, apply what we have seen before.
i don't believe in professionally grading coins unless its either a rare coin that needs authentication and preservation or a higher value coin where it makes sense to spend that kind of money. in this case, this is one coin that one should consider encapsulating
this is a tough call for a higher end coin to attribute re-coloring without seeing the actual coin. when I look at the first photos especially the obv the color is so even across the surfaces even the rims. typically what you will see with a circulated coin is that there will be areas of toning, especially the high points, where the toning would be more dull or worn down. if you look close at the reverse above the ONE in the field, you will see a lot of small scratches. in fact there are quite a few of them on the rev fields. was someone attempting to cover these? the second set of photos are a little different so that throws a monkey wrench into the equation.
i wish paralyse would chime in on it. he's pretty good at reading such things. if feel better about the second set of photos but to get that kind of consistency of color across the surfaces is not something I would think is normal . the only way to be 100% certain is to send it in.
the issue with assigning a price to the coin is the disparity of wear/strike comparing both sides and how a
TPG will assess that. we have grades here from VF20 to VF35. if can't see the coin ever coming back as VF20 so VF30 or 35 is the likely grade.
value wise, because its such a sought after coin, the difference in price even between VF25 and VF35 is between $1000 and $1100. with a details designation your still looking at an $850 coin imo