Sorry to those who followed my last posting. When I said slip jigs were in 12/8 I meant to say 9/8.Noreen and Malcolm are definitely closing in on a definitive explanation. But there is a slight contradiction between them in that Noreen seems to be saying that 6/8 jigs can be double or single ( in which case what's the difference, if it's nothing to do with repeats?).
Also Noreen, can you say anything about the difference between single and double reels? I would still hold out for my original explanation on that, to the extent that "Man of the House" in the versions I have seen printed does not lend itself to repeats and is known as a single reel. These two facts must surely be connected?