If you are using an lcd to replace you rmacintosh plus crt, you will need this inserted between your lcd and the crt casing. This version includes rounded corners and radius to match the crt curvature.

you could print this in beige or black, they both look good

FYI, if you are looking for an lcd that fits inside the mac plus, the screen from a gen 1 ipad is perfect. you can also purchase hdmi and vga driver boards with relative ease. this acan then be hooked up to a raspberry pi.