check the condition of the seals, they deform when you apply the brakes, the 'memory' of their original shape helps to draw the pistons back into the caliper body.
As previously mentioned on the site, Italian liability law means you can't get many brake spares. However these guys seem to have wide range of bits
http://www.yoyodyneti.com/SearchResu...CategoryID=164
Brembo calipers seem particularly 'delicate' in our weather, I take mine apart and clean them out at least twice-a-year.