Thanks Rudey!
Yes, the screws. All of them use the larger phillips bit. The smallest one for the upper deck has a 6mm head with a JIS dot on it, so a JIS screwdriver is going to help avoid having to press down to prevent camout. You can't put a lot of downward force on it because it screws into the upper deck's bracket and can bend. The shaft is the same thickness as a #4 (2.8mm) screw, but they don't want to go in. I ended up finding one that was 2.74mm or so, and went in with a good bite because I think its thread style was a bit different. You can always drill out the hole on the deck bracket a tad to open it up for one you find that's just a bit too big. The original screw is 13.5mm long, but I used a 12mm screw with a 5.5mm head and it still worked.
Looking at the back, the upper left/upper right/lower right are 42.5mm. The other three along the bottom and the two in the center are 69.5, and the upper center one is 19.5mm. All of these nine have 8mm heads and 3.9mm thick shafts with that highly angled, deep thread for plastics.