Bamboozled On A So-Called Monster Toned Dollar...

To each, his own.
I am not particularly enamoured with the toning of these.

The toning on the coins pictured is in a state of unstable transition. The toning in ten years will most probably look quite different to what it does now. That is always the risk, even with beautifully multi hued toning. Such toning is extremely delicate.

Gas tight encapsulation of individual coins is probably the best way to maintain the toning at the current appearance of what you may prefer. In the long term, most slabs cannot provide the sort of environmental stability required.

Museums, for a variety of reasons, usually don't bother with with encapsulation, even for their most valuable coins. They just let them continue to patinate.

There is nothing wrong with the 1971 coin. These coins (1971.72.73) were never encapsulated and depending how and where they were stored, they produced some very cool toning. I also wouldn't be so quick on the 58 either. I've seen some very dark toned scrap grade silver dollars brought into the store that were this dark as a result of years of varying storage and not AT. Although I agree that this is a $20 coin no matter how it looks. I also remember buying some specimen 1967 sets from Italy a few years back that were almost completely black on reverse with some spotty toning on obverse (facing the case side). All 20 sets looked very similar. I'll see if I can post some pics. Last but not least defining AT can sometimes be tricky. The last time I used the example of modern day RCM coins being displayed in my store windows that toned over time as a result. AT or not?

Here's one I've never seen before that I picked up in a lot. Rainbow edge toning but the surfaces are virtually color-free.

So very few 73 specimen pennies survived in those red cases that they are actually very difficult to find in high grade and problem free.