Take a look at these 2 pages. You should be able to understand the proof marks from them.

http://site.voila.fr/guideliege/modedemploi.htm
http://site.voila.fr/guideliege/page2.htm

After 1924 each gun that passed proof was stamped with the mark of the controller and the date code. The weight is the weight of the barrels after 1st proof. This was to insure that no changes were made for subsequent tests.

Pete