First consideration would be what class your preparing the car for and how long you expect to show it. The reason is that MCA may (with others possibly following) be moving away from the use of paints in place of original finishes. At first or over the long term this looks like it will be limited to the trailered classes in Concours
For the front springs MCA allows either a semi0gloss black or a heat treated/dark look. If your going for the second look the rattle can phosphate paint followed by a light dry coat of the interior Charcoal paint and finally a light dry coat of a satin clear
Don't know of spray paints that will reproduce the multi tones produced by bending and shaping the upper and lower A arms. People are typically doing the phosphate, tumble and oil (or clear coat) or the gun bluing then oil (of clear coating) from what I see
The spindles look different from everything else as they tended to get a almost painted look (dark gray) on some from the oil quenching but then you need the brightly machined surfaces also. You might be able to carefully paint them with the phosphate and charcoal combination mentioned above followed by the machined or sanded surfaces followed by a clear or oil coat.
Hope this helps
- DO have a natural parts finishing article I should get done and posted I guess