I seem to remember that Eastwood Co. sells kits for re-electroplating original metal finishes, i.e. black phosphate, cadmium, etc. All you need is a kit, some plastic containers, and a 12 volt battery.
Exactly right. These kits were used on my 69 Swinger 340 car.
Also, instead of blasting parts, use a phosphate etch to remove light rust from the metal.