I read on how you promoted the 5th Edition and that there were a free postermap you could get. In late spring there will be a convention in my town (the 2nd largest convention in Sweden, with people from all of the nordic countries as well as from Estonia, Latvia and Lithuania), Me and two of my friends will play a Ars Magica scenario there and it would be nice to have one of these to put up to make this game (and our scenario) a little more visible. (and any free brousheurs you have to give away to people).
Let me know more about your convention so I can promote it on the Grand Tribunal UK pages. I don't think Atlas do European Con support as postage is clearly an issue but try writing to Cam Banks, he may be able to help. Unfortunately I have given all the posters I had away at GT's, and I don't think I ever had a poster map, or indeed saw it. If there is any practical way us Grand Tribunal folks can help, perhaps with scenarios etc, just ask!
MAYBE you can try to contact the ludopathes. For the french subscription to Ars, we had 3 maps (paper, leather and cloth), so maybe they still have some.
I doubt it, but you can try