Well, with my last said, I have the feeling that this one toned "naturally" according to the methods considered NT - it sat for quite a while in a collection. Coins don't tone in circulation - they tone while sitting. Unfortunately for this one, it looks like that natural toning happened while it was glued to something, leaving that splotch on the reverse, and as a result it won't be considered NT. However, the color progression and physical propagation patterns are appropriate for NT.