I have the Millipede with Braze kit in my Centipede Cabaret, and I just love the Millipede game! So I really wanted to play Milli with the proper 3" trackball. As soon as Takeman took up orders on the repro CP's, I ordered a blank one. Also bought some 3" trackball units and an Irish Centi CPO.
Wet sanded the CP to prepare for the CPO. Powder coat paints has a low surface energy, so to get a better bond of the adhesive, one must abrade off the top layer.
Then it was time to drill the holes in the CP. Made a T-shaped wooden jig, to be able to clamp the CP in the drill press. Drilled the holes for fire button and trackball with 29 mm and 3" hole saws, and the other holes with drill bits. Worked as a charm!