Thanks guys, brilliant feedback.., i share the worry of steel shot getting stuck inside Didi, though using a magnet could solve that. My pieces are 8mm in diameter the max diameter of a hole in each piece is just 3mm, so i'll test on some copper first and settle for a pickle finish as dennis suggests for now. Thanks Dennis and Carol, cold connection is a great idea too. Looking into a bayonet design for one of my pieces actually. I am using the everflex rubber disks, instead of radial at the moment, before polishing as I am also afraid of the rouge gumming inside. Hoping as Kwant says - No one will notice.
Thanks for the replies.