Thanks for checking.
Great find on the slings! Those British slings look like the might have cording woven into the edges. In any event, even f the right width, there are too many stitches in the center section. (I'm looking for 14 pairs across, minimum 42" lengths.)
Even though I can't use the UK slings, it's sort of a rush to find out about stashes of NOS existing, of anything. Now there's the time machine you were talking about...
Chris