you have a tab that is called #2, it connects to the powder measure, the spring is called the powder measure return spring. I see the tab on the bench. There are 2 special screws that attach to the shell plate and drive the index rod, I see the index rod, I do not see the two screws, the index rod has a big end and a small end.
The rod that is connected to the powder activated system seem to me like it is in a wad on top, I would suggest you remove the case counter, complete the assemble, then install the case counter after you get started.
F. Guffey