now for starters .. get the part glass beaded then wetsand with 220 to 1000 grit at that point you should have a satin /smooth surface finish
start with a sisal/black hit it 2-3 passes in the cut motion
then change buff's to a sprial/black combo you will get a nice shine in the color motion .
then switch over to a new buff ... sprial / green color motion
then to loose /red color motion
finish off with either high grade carnuba wax of clear urathane ...

that is how i do steel part's and i get a chrome like finish everytime

if you want plating start a new topic in the electroplating