Ive got all the necessary equipment for parkerizing hardware,.... but rattlecans are so convenient!
Duplicolors' "Cast Coat" mimics the grey varieties, and can easily be darkened with a litle flat black overspray.
For the greenish-brown manganese varieties, I use Silathane "Bronze".
Using "Steel Wheels" as an undercoat, you can mimic many of the textures of different parkerizing as well.
The AMCA judges have been known to knock off points if all of the parkerizing on a machine didn't match. The truth is, it should be docked if it all DOES match!
One reason I use a lot of paint is that I can PRESERVE and cosmetically enhance original hardware without destroying the original finish. A quick dip in paint remover brings it back to museum grade.
And since a lot of my people aren't into doucheing their entire bikes with WD-40, or painting every nut and bolt with Vaseline like they should, the paint is a lot more sanitary and easy to maintain.
Ever try to touch up a scratch in parkerizing?