I spent a long time going through the paint chips at my local car paint suppliers and came up with Chrysler Pss-1 Silverstone Pearl Metallic as the closest. I used it to re-do the clutch cover on my old AL2 as I'd rubbed through a bit with my boot. Edge to edge next to the existing you couldn't tell it had been painted.
It is a base coat & lacquer job though.
As far as prep goes, the finish reflects the time you spend getting the substrate ready. Any loose paint has to go and then prime. Depending on pitting of the case, you're maybe looking at high build primer & flattening between coats.
As a rough & ready job, attack it with scotchbrite until it's smoothish looking & paint on that. You can often get away with very light coats of the base colour instead of primer.