If you specifically need the original file:
If you want a font that looks exactly like Grotesk S Sh Book without legal risks, here’s what to do: Grotesk S Sh Book Font Free
TeX Gyre Heros is an optically corrected clone of Helvetica, but its "Book" weight has been adjusted to fit the Grotesk S Sh architectural metrics. It is the gold standard for LaTeX users. If you specifically need the original file: If