Spoke with Mr. Moreman tonight, He was a BS&R's Salesman and ended his career as their Sales Manager when he retired from the company. He was with the company from 1951-1972 or 1973.
When BS&R switched to the DESI machines they did change to the tab type handle, they called it a "wedge handle" For the "Critical Market" items, they very quickly figured out a way to make the loop handle and used only the looped handle design, no wedge handle was ever used on these items. This includes the DOs and Skillets as they used the same lid. He does not remember any skillet or DO lids ever using the wedge type lid. The BS&R DO with a wedge handle I saw must of been a marriage of a DO and a Kettle lid
Other items: sauce pans, (1, 2, & 3qt) and items that would be used outside over fires got the wedge handles. Outdoor use items included: CO's, Camp Three Legged Skillets, & Kettles.
They used the wedge lid on CO's for many years, maybe 10 years, maybe more, per him. It wasn't a priority to change, as it was going to be used outside, primarily by men, not women, and they assumed that the man would have the strength and/or tools to remove the lid. This would explain why so many CO's are seen with the wedge handle. When they finally changed the CO to a looped handle he wasn't sure.
About your comment that it would be nice to have a bunch of the old foundry guys around, I'd love it, I just wish I could get the few I know in the same room at the same time and see what they could remember collectively.