I haven't done it yet, but it doesn't look like it will take much. The small lip at the top of the CP will have to be extended. I think I am going to just replace that whole piece with a larger one cut from aluminum. The back of the box will need to be extended so I can drill holes that will match the Konami mounting holes. I think I am going to try just adding a 1x2 poplar board across the opening to see if that will do it. I think I have one laying around.
If I get to this this weekend, I'll let you know how it goes.