Just appeared today at www.leboncoin.fr a 44 button Charlie Jeffries anglo in D/G... for a very interesting price. Location is Paris region.
To view go to the above website and enter via clicking on the map of France , then type "concertina" in the lefthand box... scroll to "instruments de musique" in the middle box and to " toute la France" in the righthand box and click the box "chercher"... voila !