Are you and crammet 442 really close friends, hmmmm....
crammit442 got to me too, but currently I still have my OEM box. Tl is on order though.
Regarding the screws, they are a custom pitch. Since you are going into plastic, however, you could find something close that would suffice.
Because I am anal, at one time I went to the Yamaha dealer and paid $1.00 a piece for new ones (the heads were stripped like I assume that you are experiencing).
Contrary to what others have stated, you WILL have trouble removing these screws at one point in your life. I have used small vise grips in some cases.
Like others mentioned, use the largest screwdriver that fits, #3 Phillips I believe.