What are you using to pressurize the stove? It looks to be some type of screw, but I cant really tell.
It's a wingnut with a small machine screw in it... but it is not screwed into the hole; the hole is big enough that the screw just sits in the hole. I was using a coin, but the pressure was high enough to make the coin rattle, so I use this. Also, this is magnetic, so I store it in the little orange gripper that came with my GSI Minimalist cookset (the gripper has a magnet molded into it).