The earliest I can now remember, was a '48 chevy. It was under the seat on the drivers side.
I'm still looking for the "official" word on it, and looking at the '46, I found the tool list (see attached excerpt)

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2019-09-03_852x367.png (55.69 KB, 84 downloads)


'64 Chev C20 LWB stepside (Ol'Blue)