If you are looking for a "home brewed" solution...there are some spray can choices..
http://www.eastwood.com/eastwood-zin...e-aerosol.html
last set I did were media blasted first...surface had a slight texture to it...I primed with a grey primer...then a light coat of detail grey and a finish coat of the Eastwood product...they looked pretty nice. A high end resto probably deserves the full monty...but, this will work for most folks.
wilma