The 757 was the last bird drawn by hand on vellum, and the last with a wooden mockup. We mostly used calculators on formulae pulled from the Boeing Design Manual (a treasure), or derived formulae as needed. Some of the draftsmen did calculations by drawing geometric shapes and measuring them, which I'm sure is a lost art now.

We were mentored by greybeards who worked on the B-47 and 747, and sometimes would still use a slide rule. I received quite a wonderful education from those guys.

I was the first flight controls engineer, that I could tell, who stole time on a PDP-11 to much more efficiently do my work beyond what was practical with a calculator. (I was called on the carpet for that, the manager of the computer center wanted me censured for it, but my boss's boss's boss went to bat for me and told him to fork off.)