Here's a mazurka I learned off the compilation, Accordeons Diatonique en Bretagne. On that recording it was played by Christian Desnos. I don't know if that makes it a "Breton" mazurka or not, but it's a good tune. For more mazurkas, I invite you to go here and here. Also, you can check out Melodeon.net's "Theme of the Month" -- featuring mazurkas -- from some months back.