Known also as "Proinsias Ó Mhaonaigh's Mazurka #2", or "Vincent Campbell's Mazurka #2"; pretty much everybody who plays the tune learnt it (at whatever remove) from one or other of them.  I'm rather fond of it, too.  The Mazurka arrived in Ireland probably around the 1830s, and was very popular at house dances in the North.  You can find more of them at  J C's Tunefinder  -search for mazurka.

Malcolm