The Breto dance tune is called "Gavoten ar Menez"
‘Gavotten ar menez’ isn’t the name of that specific tune: it’s a breton generic term for ‘mountain gavotte’, ie; from the high plateaus(!) of central Finistère. (as in: ‘the Highland fling’)
It seems as if there’s very litte reliable information in English about Breton Dance, on the net. Try http://dansal.gwalarn.org/gavottemontagnes.html for an overview -in French- or publications by Jean-Michel and Yvon Guilcher for first hand -and first class!- accounts and theory.
I’ll post you an ABC if you’re still interested.
nb: The track "Marie-Louise" sung by Y-F Kemener on:
is very close to the Rince Briotánach track here.