Step 3: Clamp together and cut out the wing nut holes
Before we glue everything together, we need to cut out some holes so that the wing nuts can secure directly to the steel plate (in the plane of the base board). Decide where you want the two holes and then clamp all your boards together. 1 1/2in provides enough clearance for the 3/8ths in wing nut and 1 1/4in is big enough for the 1/4-20 wing nut.
Note that mounting these holes away from the center of the board is not a bad idea since the center of gravity of your computer will be offset to one side when the screen is raised.