Just like Galway Bay, this was a song that I grew up with and was considered to be a typical Irish song. In 1993, whilst in the Irish Pub in the Bremen Schnoorviertel, I was obliged to learn it at the insistence of one Jenny Edgell, the wife of a great pal of mine, who maintained that no folk singer worth his salt should not be able to perform it. And I must say, I am obliged to agree with her!!
I found the version for me in good old Soodlum's 100 Irish Ballads Volume 1.

Surfer Bob MaClure sent me the following useful snippet on 2nd March 2001
"I'll Take You Home Kathleen" is not, in fact, a tune of Irish origin. It was written in 1875 by Thomas Westendorf, a public school music teacher in Plainfield, Indiana, and was the first public performance of the tune was in Plainfield's town hall. Westendorf wrote the tune for his wife Jeanie, while she was visiting her home town of Ogdensburg, New York. In 1876 it was one of two most popular songs in America - the other being Grandfather's Clock.
Thanks a lot Bob!

Lyrics