Quote Originally Posted by AgX View Post
I am confused by now...

So, there are stainless-steel center-loaded reels each with a different type of fastening mechanism at the center and there is one such center-loaded reel that has no such mechanism at all?

That one in the first photo above (inserted into post), without mechanism, still seems to have the wires bent in a way that film might be stuck inbetween.
The hooks aren't used as hooks, but rather as starting guides.

135 film is stiff enough that when you crimp it slightly over a bar it won't slip out. So when it goes from the crimp into the spiral, it stays there.