I think it has less to do with time and place and more to do with a sharp person who understood differntials and knew how to communicate that knowledge effectively in a very simple manner. I think that a pretty high percentage of people who knew exactly how and why differentials worked couldn't have come up with that simple model to explain it to the ignorant.
I've looked at a number of differentials in my day, saw what was happening but didn't understand it.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13