rebuilding Carter 4426 (few questions with pics)

Hey guys I just opened up my Carter AVS 4426 for rebuild and have a few questions.
1. Is this the correct area for the needle in picture #1 ?
2. My rebuild kit came with 2 little round rubber seals is this where they go, or are they even needed? picture #2
3. Are these 2 screws my air mixure screws? They where tight in there holes and have no springs? Pic #3
What is the purpose of this part as you can see it was broken? Picture #4 thanks gor any help guys..