This might be the most obsessively nerdy thing I've ever seen. One of the bronze ‘H’es in a sign was installed upside down, and the author dove into historical research to find out when and why.

https://www.inconspicuous.info/p/h-bomb-a-frank-lloyd-wright-typographic

H-Bomb: A Frank Lloyd Wright Typographic Mystery

The famed architect made a surprising error on one of his most notable buildings — or did he? A deep dive to uncover the truth.

Inconspicuous Consumption

I just remembered that I have ALSO blogged about erroneous sign typography. AND like this author, I pulled in Jonathan Hoefler to consult!

https://blog.plover.com/IT/typo/typographical-mysteries-of-yeadon.html