The elevator control arm is built in a similar manner, mounting parts and completed control arm shown below.
The screws and washers shown bottom left are the motor mounting screws. The smaller ones are much easier to fit than the larger ones. Consequently I didn't use the larger ones.

Having built the rocker you should end up with something like the pictures below.
I have highlighted in red the screws that mount the rocker assembly to the elevator assembly.
These screws should not be overtightened or your elevator linkage will be very notchy and not move freely.