This is something I first posted about ten years ago. My brother is a retired Chrysler engineer and lives in a suburb of Detroit. One of his neighbors, who was a retired designer for GM, passed away. When his kids cleaned out his house they tossed a bunch of GM manuals from the early 1960s, and my brother grabbed what he could from the dumpster before it was hauled away.
The manuals aren't the sort of thing you would expect. They mostly describe the elements of GM graphic design for logos, symbols, and text as they were to be used for signage or package labeling. They show how to lay out signs for use in GM offices or factories, and how to design boxes for parts (the familiar boxes you'd see Delco ignition parts in, for example.) Included was this diagram showing how to correctly draw the Pontiac arrowhead, and an example of the Pontiac typeface (called 'Pontiac Gothic'.) Interestingly, the manual says the letters are for "use in headings and display copy, but should never be used in text." There are two different versions of the 'M' for some reason.
I don't know for sure but the font may be useful for some labels and stickers on the car.
