1975 D LMC Beautiful Rainbow Toned

I lewan toward AT as well.

Just be aware, the toning will continue to change. The are two camps on these, one loves them, others just consider it damage. If you like it, keep it. I think they are cool overall

If I were to see that one up for sale. My gut would also tell me Artificial Toning. But my gut could be wrong. Wouldn't be the first time. L It's unlike any I've seen in a roll.

Here's the thing
I have a bunch of LWC/LMC in an original green Meghrig album that I can definitely state was put together in the 1960s.
The reverses on some of them (board/paper side) have similar toning, but the obverses are completely normal and have no toning (the plastic slide side)

I find it slightly less likely this is natural toning on the obverse, it would require a rather specific set of circumstances. Could be chemical damage that resembles toning (surface contamination/ED.) That being said, why would someone waste time doing a thoroughly mediocre AT job on a common-date AU Lincoln cent?