Die cast repair/acid copper

I have a chrome plating business in Olathe, Kansas and we do a lot of die cast automotive parts. I am new to acid copper and need to learn about it. My question is with a severely pitted part - How long do I plate it initially? Do I plate it for several hours or plate it for a shorter period of time, polish it and replate it again? What buffing compound is best to help "buff" the pits away? Also what is the best way to control the burning and build up on the edges? Is there any book or other resource that deals with die cast repair/ acid copper plating? Any help would be greatly appreciated.

Also I've seen some companies that are filling the pits with filler and then spraying a conductive paint on the parts. How does that work and where do I get the materials?