Strange that in the first clip, they all had horizontal drawing boards. Tilted boards are so much easier. I doubt that they were engineers. Back then engineers were too valuable to spend their time on a drawing board, except in small businesses. Drawing offices were staffed with people labelled as design draftsmen and draftsmen. Even in my first job as an engineer after graduating I was given a drawing office staffed with draftsmen.
Nowadays "engineers" are taught how to be CAD jockeys instead of physics and mathematics. Just like managers who now type their own letters (now called emails) instead of managing. Typists used to do that lower grade work.