I don't know anything about this tune apart from how it goes, or sort of how it goes. I do know some Jimmies and have met an O'Reilly or two, but that probably doesn't give me much to base a tune blurb on here. So there'll be no blurb. Enough to say that I like this tune because it never quite goes how I'd expect it to.    The session.org has some (occasionally strange) versions here.