It depends what files you want to find. Basically, you should look on the French military historical service website: http://www.servicehistorique.sga.defense.gouv.fr/
You can do some search online http://www.servicehistorique.sga.defense.gouv.fr/?q=content/les-instruments-de-recherche
But it says "unless noted in red, all documents are available at Vincennes". It means you win yourself a trip to Paris.
You can find the Military justice archives references here
Actually, you may have to go to Toulon since it looks like the archives of the First permanent war tribunal are there. Other war tribunals archives are in Paris. So it really depends whose files you are looking for.
" Première Guerre mondiale Conseils de guerre :
Au SHD de Toulon :
I understand that data is already available online here: http://www.memoiredeshommes.sga.defense.gouv.fr/fr/article.php?larub=211&titre=fusilles-de-la-premiere-guerre-mondiale - it lets you browse the files on all executions ordered by the military justice during WW1 (around 1000 in total).
I don't know anything about this. Can someone provide me with a good source?
As a side question, can someone explain what these French Army mutinies were, and what, if anything, could be found in classified files that would be previously unknown or unaccounted for?
Any truth to the rumour that a lot of what should have been de-classified this year seems to be missing and/or incomplete?
If I may ask a follow up question, what is the oldest item/document that we know of that is still classified? I heard that info regarding Jack the Ripper is still classified as it may relate to the Royal Family. Also, what is the longest classification date for items created today? Eg are there any governments that require a 300 year classification, maybe Turkey with records of Armenia as that can inflame tensions there for generations to come?