Mark,

That's interesting, I had thought about cutting a thin metal sheet to cover a larger area and then cutting rectangular holes, but I wasn't sure if the sheet could be attached to the cardboard. I hadn't thought of making metal washers with rectangular holes and then resining them in place. You may be onto something there - there has to be a lot of Mark II's with that problem!

Because of the stitching and biscuit padding, option #2, peeling the leather back, is way beyond my pay grade.