Thanks, Jim! That's the kind of dancing I could watch for hours. It reminds me of the way some of the old-timers would stepdance in Cape Breton and Prince Edward Island. For example: https://www.youtube.com/watch?v=fmTIVbL8dGw&index=39&list=PL2B140A87D3310B23

I suspect that Bobelix is right - that this sort of thing was widespread in the not terribly distant past. It would probably be next to impossible to find one place of origin for it ........