Does anyone what the "international symbol dictionary" Susan Kare used was?
If I had to guess, I'd guess Henry Dreyfuss's Symbol Sourcebook. It was published in 1972, and it seems plausibly the sort of book someone like Susan Kate might have had to hand in the early '80s. https://www.societyofsigns.com/projects/symbol-sourcebook
Unicode does not quite cover it because it lacks context and meaning of combined codepoints.