I'd be VERY surprised if it was possible to inhibit/re-enable a basic feature of an ammo box or container.
Switching on and off "Gear" seems impossible to me.
If you are using UserActions to Open/Close the door, instead I'd suggest creating an an additional addon, an invisible ammo box (has GEO, memory, view lods etc, but very very small or no Resolution LOD) and spawning/AttachTo that box inside your safe when its open, via the same script to animate the door open, then deleting (or detach and setpos[0,0,0] on map) it once the door is closed.
Make sure the center of your safe is hollow in the Geometry and ViewGeo Lod so a player can interact with something spawned in its center.