Good progress.
Here's a pic of the bracket and return spring. The spring isnt anything special. I bet you can find something at a local hardware store that's the approx length and tension.
In the pics, your throttle cable is disconnected, and it's the wrong kind for this carb. The pcv hose is loose, big air leak. What is the big manifold vacuum line connected to (the SAE made in Thailand hose)? I don't see any fuel in the sight glass either. Is this how it's currently set up, or...