Tim the Thatcher
No. 375 in O’Neill’s 1001/ No. 739 in Music of Ireland: 1850 Melodies.
The title in Irish is "Teig/Tadg an Tuigeadoir".
Bizarre that no-one has posted this before, even though it is not a commonly played/well known tune SFAIK.
This A minor transcription is accurate to the setting found in my copy of O’Neill’s 1001 and is the one given by Frank Nordberg (http://abcnotation.com/tunePage?a=trillian.mit.edu/~jc/music/book/oneills/1001/T/TimTheThatcher/0000). There are several other ABC settings of it online (including the usually reliable Fiddlers’ Companion - http://www.ibiblio.org/fiddlers/TIA_TIM.htm#TIM_THE_THATCHER - Andrew Kuntz even quotes the same source!) which mysteriously set it in A major, though at the same pitch (also e.g. http://abcnotation.com/tunePage?a=trillian.mit.edu/~jc/music/book/oneills/1850/X/0739_bs/0000). It really, really doesn’t work as a tune thus!
Could this be a case of GIGO/Chinese Whispers? Maybe one historic ABC transcriber missed the "m" in "Am" in the K: line and others have simply copied and pasted? Or is the setting in the full (Music of Ireland: 1850 Melodies) O’Neill’s actually given in A major? I don’t have that to check, but if so I’d suggest it represented a type-setting error with the key signature, corrected in the 1001, not an error in the latter - on melodic grounds.