I figured that I would add my two cents to this thread. As far as the first Morgans go, I agree with the comments that GDJMSP has made about bag toning and the such. To me, the Morgans shown at the beginning of the thread have a natural look to them. The cresent shaped toning lines and the color progressions look natural to me. I am not surprised that a TPG would grade these. However, I am not saying that these types of toning patterns cannot be copied or imitated. But to me, they have a "natural look," and were subsequently graded. The 1899-O shown later looks very natural to me. Its just a circulated piece that has tone up over the years......no problems there. I think the real question comes down to the definition of NT vs. AT. If a coin sits in a drawer for years, improperly stored in an envelope, then it is considered NT. However, what if someone sits that envelope in a window sill, or puts the coin in a piece of cloth exposed to moisture? These coins may tone "naturally," and may even be graded. But are they NT or AT? What about NT that has been "helped" or accelerated? These are some very important issues in our hobby right now. Sorry for the long post.....just some thoughts.
That IS AT.....because you have accelerated it. If you had left it lying on the floor for that time, would it have toned as much ??
By that definition placing coins in an album would be AT as well - just about anything would be AT would it not ?