Anyone have 2 barrel carb ?

I just bought a 73 Duster with a 2 barrel 318 a couple day’s ago. The previous owner installed an aftermarket Carter BB 2 barrel I believe. I’m just getting familiar with this carb and intend to leave the car as a 2 barrel. I worked out some bugs and an improper choke adjustment, etc. Car is running a lot better now. I wanted to verify this vacuum hook up. It is attached from the side of carb to the top fitting on this mechanism in the passenger corner of firewall. What is this mechanism ? The vacuum advance on distributor is hooked up to the bottom port of that same mechanism. I want to verify previous owner has this hooked up properly. I worked out all of the bugs and tuned the carb properly. It’s now running a lot better. Where prior to me going over it. It would stall and shut off once it was warm and sputter under acceleration. The choke wasn’t opening completely once warm. The V shaped rod connecting the choke vacuum to choke rod needed squeezed tighter together to take out the slop on this choke set up. Can someone verify these vacuum connections being correct or not ? Lastly, what is the connection that is plugged in the 4th picture ?

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