I remember seeing a picture of an apprentice instructor at Brown & Sharpe who was dressed similarly, but with jacket off and white shirt sleeves rolled up; nothing wrong with a bow tie so far as safety is concerned, just long loose ties; back in the day some guys would wear a long tie, and tuck it in between shirt buttons. I can't imagine that many production machinists dressed like that, but perhaps toolmakers and perhaps high status patternmakers; things were different back then. When I worked at Kaiser Steel, there was a black man, Ralph Ruff, who came to work in a white shirt and tie, but changed into work clothes in the shop; we thought perhaps he'd had a better job and could not find anything else but out dirty hole, but still had to impress his neighbors when leaving for work on swing shift; coming home after midnight would have not been a problem ---