In a long roundabout way I landed on a site with an enormous number of gig recordings, mostly of a non traditional variety. But among alll the rest there are some Planxty concerts archived, recordings of very fine quality, from the 1979 After the Break European tour, the first time I saw them play live. At the time they were Lunny, Moore, Irvine, O'Flynn and Molloy.
Here are direct links to MP3 streams:
Planxty 1979-03-three tracks on WDRPlanxty1979-04-24UniMensaBremenGermanyBoys of Ballisodare festival, SligoThey come from
this page where there are also downloads in various formats and set lists available.
{add} I have poked around the site a bit, nothing much traditional to be found but there is a bunch of Chieftains concerts from 1978 to 2012 and a number of Christy Moore ones as well, if you're into that sort of thing.