Researcher Keith Janes, in his Conscript Heroes website (http://conscript-heroes.com/index.html), devotes a page to the escape network at Hornoy le Boourg and Amiens.   See http://conscript-heroes.com/escapelines/EEIE-Articles/Art-12-Balfe.htm#TopPage.  He gives credit for some of the information in that page to fellow researchers John Howes, Oliver Clutton-Brock, Luc Vervoort, Edouard Reniere, Philippe Connart, and Dominique Lecomte.