Your "main" screws (group of 3 on the right) are a standard, called a "#8-32"
This means a hole size #8, and 32 threads to the inch.
Length is almost exactly 1 centimeter (3/8 inch)
So, all 6 screws on the left, and all 3 on the right are this size, just different length (1/4 inch).
And the ones on the left have the "star" washers installed.
#8-32 3/8 in
And
#8-32 1/4 in
And these should be the long screws that hold the back of the 2 halves of the plastic case together:
The smallest ones in the middle-front of the above picture I have yet to measure and document.
