A participant writes about the early days of numerical control machining and also discusses how definition of complex aircraft shapes was done prior to the computing era. Imagine the labor intensiveness of that process, which descended from traditional shipbuilding techniques but surely required a much higher degree of precision when applied to aircraft production.
A Bendix G-15 computer was used for the NC work described at Northrop, with paper punched tape as the communications medium between the computer and the machine tool. There is a Bendix G-15 at the American Precision Museum in Vermont, along with many machine tools and other interesting exhibits–see my post here. Recommended visit for those interested in the history of technology.