This it a reproduction of the MCR board mounting bracket for Bally Midway's MCR games such as Tron, Tapper, Spy Hunter, Kick-Man, Satan's Hollow and Discs of Tron (among others). This is the bracket that goes below the PCB stack and supports the base.  Please note, some MCR games with metal plates had a different spacing to hold the metal plates.  This lower bracket will work but the boards will have a 5 degree tilt (or it can be ripped to the right width)