Many documents in the "Early Copyright Title Pages" project begin with a number, often handwritten. The word "number" is often abbreviated, with a capital "N" followed by a superscript "o" and a period. There is a typographic mark for this abbreviation, called the "numero sign" or "numero symbol." (More on this symbol here: https://en.wikipedia.org/wiki/Numero_sign)
In Unicode, it looks like this: №
My question: where an author has used this abbreviation, should it be transcribed using the Unicode numero sign? Does it make a difference if the author writes the "o" in superscript or not? What about periods, which authors often use but which the Unicode sign omits?
I realize that this question is ridiculous! But as a typography liker, I couldn't help but ask it.