The 1980s "Kornog" tune is as Martin Carthy recorded it back in 1972, though Kornog take it at a far faster pace. Martin commented (sleevenotes, Shearwater, Peg Records PEG12) "I have to thank Phil and Sid of Edinburgh for the original idea which led to me recasting the tune sung to 'Lord Randal', known as 'My Wee Croodlin' Doo'."

I'd think that Kornog got the tune (in that form) from Carthy's record, and re-set 'Croodlin' Doo' words to it (Carthy uses an English, or anglicised, text). It's a pity that they don't acknowledge their source in their own sleevenotes, as Lea suggests; I've only heard a short extract of their recording, which can be heard at http://www.arbedkeltiek.com/saozneg/music/kornog.htm#4.

What seem to be unusual time-signatures to us nowadays were often quite common a few centuries ago, but in this case I suspect we are dealing with an interesting, but not traditional, modern innovation; and that it was copied from Martin Carthy.