This should get you pretty close, but you may need to finesse it to fit your machine. I measured it so you have two solid boards that you can start with, and then I have the measurements for the areas that are cut away to fit the playfields. In the screen capture example, the bottom two boards are the starting boards with cutouts lined up, and the top two boards are with the finished cuts.
Left Side
Starting Board - 33.625 x 1.688 x 0.5 inches
Upper Cutaway - 6.625 x 0.5 x 0.5 inches
Lower Cutaway - 27.125 x 0.50 x 0.50 inches
Right Side
Starting Board - 38.00 x 1.688 x 0.5 inches
Upper Cutaway - 9.00 x 0.5 x 0.5 inches
Lower Cutaway - 24.625 in x 0.50 x 0.50 inches
Flash Gordon Rails (resized).jpg