Just a point of interest.....
I grew up in the east end of London (Walthamstow). Up until the 1950, or there abouts, there were many, many Jewish families trading in the markets.
Indeed, one of the most famous markets, Petticoat Lane, the main trading day was Sunday as the Jews didn't work on Saturdays. It was the same in Walthamstow market, in that the shops and stalls run by orthodox Jews were not open on Saturdays. The Jewish bakers were close on Saturday but did a roaring trade on Sundays (fresh bread

).
I also had a good knowledge of the fruit & veg wholesale market of Spitalfields and the wholesale meat market of Smithfield where kosher meat was always kept separate and overseen by rabbis to ensure it was not contaminated by contact with non-kosher products.
At the same time, the non-orthodox Jews did trade on Saturdays for as long as I can remember
