Dano,
If you haven't figured it out already, the fuze will unscrew from your submunition showing it to be hollow inside. Also, you can unscrew the screw in the middle of the fins in back, which will relax the spring plate that is holding the fins open, so you can fold them back in closed position.
The Viet Cong would make them into boobytraps by removing the fins from the unexploded ones that would catch in the trees, and stick the bomblet in a suspended tin can, with a tripwire across a trail connected to the bottom of the can. When the tripwire was pulled, the submunition would fall out so the fuze end hit the ground and detonated.