Fogie,Don't want to 'politicise' this thread, but if its a GB thing Liam is out by definition. Not sure about Andy, who is nicknamed "the man from God knows where". :-)
The band that John McCusker & Kate Rusby tour with have a lot of those listed above - John McCusker, Mick Mc Goldrick, Ian Carr, Ian Seward, Andy Cutting. Also had Gino Lupari last time I saw them, but he doesn't qualify on the GB rule, and is probably too busy on the Drumcree thread.
In my opinion you mentioned the name of the ultimate folk/dance band in your initial posting - I've never seen better than La Bottine, except maybe the Bothy Band on a good day.