Hi Fredrick, Sorry, I don't know this song. If I've ever heard it, I don't remember it. However, FYI, if you are interested in learning to play it, "Star Of The County Down" is on a Steve Kaufman video "Learning To Play Waltzes," available from Homespun Tapes. You can find their webpage on the Internet at homespuntapes.com.Steve Kaufman is a dynamite flatpick guitar instructor and the starting level for this video is early intermediate.
I have no financial interest in Homespun or Steve Kaufman products, but I have learned a bunch from him & recommend his work highly.
Take care,
Randall