I'm not really sure how this worked. This one was sold through the internet as a prototype, but no documentation is known to me. Cast iron body, alloy fuze and a brass safetycap. The body is marked SFM (Societé Française des Munitions). My guess is that the safety fell out when the grenade was thrown, releasing the striker which was driven downwards into the primer. A bit like the 1935 fuze?
Do you have a suggestion?