Some info on the details on the above carb from a expert on Quadrajets.
The choke blade and secondary air doors should be clear (silver), not yellow chromate. The only air doors Iíve ever seen that were yellow chromated were on some Pontiac carbs, and even then it appears to be hit-or-miss.
All of the screws should be black (black chromate was originally used I believe). The screws holding the air doors & choke blade on are the wrong style of screw as well.
Both primary & secondary throttle shafts (just the shafts, not the entire assembly) were originally coated in green Teflon before the operator mechanisms were peened on. Since itís not feasible to disassemble the operator mechanisms from the shafts, they are typically stripped and plated in zinc (or cad, depending on whoís working on it) and subsequently yellow chromated.
Many of the small wire links (choke rod, pump arm rod, etc.) were originally clear, not yellow chromate. The idle adjuster screw is usually clear as are most of the external misc. springs. Same for the idle mixture screws & springs.
The big white nylon gasket behind the inlet fitting is a sign that the threads were heli-coiled. Most often the repair isnít square to the original threads which causes the inlet fitting to leak around the perimeter since the (repaired) threads are no longer parallel to the sealing surface. The Teflon gasket compensates for some mis-alignment and helps seal the inlet fitting. HIC covers can be clear or yellow