BitSavers has just posted scans of Control Data Corporation‘s Integrated Computer-Aided
Engineering and Manufacturing (ICEM) Engineering Data Library (EDL) as used on the Control Data Network Operating System (NOS). ICEM was a minor player in the overall CAD market, but ICEM Surface gained a prominent position in car body design. You can browse the documents on BitSavers.
For an overall history of the CAD industry, I recommend David Weisberg’s online free book The Engineering Design Revolution.