Grab your wrench looking piece of linkage and hook the wrench portion on the bottom of the carb.
Then hook the little spring on the back up and run the screw through it. Don't tighten it.
Here's a side view so you can see. You need to make sure the wrench shaped linkage is hanging on the screw you just ran in, not butted up to the carb. THEN start screwing it down. It should move freely once you get it screwed down.
Put the link that looks like an "S" through the bottom part
Then the top.
And cotter key them both.
Now find a gasket to fit the bottom of "the bottom plate". This one obviously belongs in an art bucket at a pre-school. It doesn't fit. I have to say that for legal reasons so you don't try to use it and cause a thermo-nuclear reaction in your intake manifold.