I think your screw count is off on the ear screws.
Flat head screws are for the ears. There should be 4 long (7/8") and 2 short (1/2").
Phillips head screws are to connect the back and face, 2 on each side. These will be covered by the ears.
Washers and nuts go on the inside.
Someone please chime in if I'm incorrect. I'm new at this myself.