I doubt this is BS&R. BS&R got their start around 1910 when they bought a defunct foundrie's patterns of stoves and hollow ware. From all the info I've gathered the handles have always had the deep V shape, I will double check this however. Many foundries used molder's marks, many paid by the piece.
During FDR's time in office, "his people" tried to force a minimum wage on the foundries. According to S. Jones the owners of the foundries fought this. They were concerned that there would be no incentive to work hard. No matter how much or how little you did, the pay was the same. They were finally able to keep the piece work scale. So others might have used the molders marks to pay their workers, not just BS&R.
The question I plan on asking is, did the patterns have a mark on them already, and the molders "check" them out for the day, or did each molder have their own distinct mark that only they used, possibly for their entire career?