Well, unfortunately, you are incorrect, by a very obvious fact.

Group A remembers it one way.
Group B remembers it another way.

If it was, like you stated, a lack of accurate memory, then there wouldn't be any groups, it would be a splatter graph around the "correct version".

But, that is not the case.
That there is a very large group of people that distinctly remember something different is entirely out of probability that it was error.

Now, the stupid penny...

Coins, to most people are meaningless chunks of metal.
No one knows or cares what is on them.

If they did, people at the FED and the mint would be up on serious charges for crimes against humanity.

Further, the image you gave from the psyche book, several of the images are correct... as long as you weren't specific on the year. So, you are asking something only a numismatist would even know.

Lastly, one more piece to disprove your suggestion that it is all a failure of memory.

In many of these cases, i remember two sets of pasts.
Yes, you read correctly, i remember what group A is saying, and i remember what group B is saying.

And so, let the understanding of multiple universes commence.
Science will just have to throw out their books and start anew,
on a new frontier.