There are 2 sites with Belgian proof info:

http://www.littlegun.be/arme%20belge/a%20a%20artisans%20identifies%20gb.htm

This site is entirely in French, but has some very good information:
http://perso.orange.fr/mallorquina/source/page0index.htm

For help with German proofs.

http://www.germanguns.com/questions.html

You may want to take some picturesof the proof marks and post them here. You will certainly get some responses.

Pete