Eh. So, parts were quite interesting, but the list of everybody who ever had an idea for a irony or sarcasm mark was getting tedious. Also, i don’t believe the idea that # comes from ℔. The octothorpe is always just two pairs of perfectly straight, parallel lines. That is quite different from the & ← et story. The great variation of &s in different typefaces, many quite et-like, makes it very different from #. (Oh, and recently i learned about ⌗ along the better known ♯)